diff --git a/src/main/java/world/bentobox/challenges/panel/admin/ManageBlocksGUI.java b/src/main/java/world/bentobox/challenges/panel/admin/ManageBlocksGUI.java
new file mode 100644
index 0000000..032fe72
--- /dev/null
+++ b/src/main/java/world/bentobox/challenges/panel/admin/ManageBlocksGUI.java
@@ -0,0 +1,224 @@
+package world.bentobox.challenges.panel.admin;
+
+
+import org.apache.commons.lang.WordUtils;
+import org.bukkit.Material;
+import org.bukkit.World;
+import java.util.*;
+
+import world.bentobox.bentobox.api.panels.PanelItem;
+import world.bentobox.bentobox.api.panels.builders.PanelBuilder;
+import world.bentobox.bentobox.api.panels.builders.PanelItemBuilder;
+import world.bentobox.bentobox.api.user.User;
+import world.bentobox.challenges.ChallengesAddon;
+import world.bentobox.challenges.panel.CommonGUI;
+import world.bentobox.challenges.panel.util.NumberGUI;
+import world.bentobox.challenges.panel.util.SelectBlocksGUI;
+import world.bentobox.challenges.utils.GuiUtils;
+
+
+/**
+ * This class allows to edit material that are in required material map.
+ */
+public class ManageBlocksGUI extends CommonGUI
+{
+	public ManageBlocksGUI(ChallengesAddon addon,
+		World world,
+		User user,
+		Map<Material, Integer> materialMap,
+		String topLabel,
+		String permissionPrefix,
+		CommonGUI parentGUI)
+	{
+		super(addon, world, user, topLabel, permissionPrefix, parentGUI);
+		this.materialMap = materialMap;
+
+		this.materialList = new ArrayList<>(this.materialMap.keySet());
+
+		// Sort materials by their ordinal value.
+		this.materialList.sort(Comparator.comparing(Enum::ordinal));
+
+		this.selectedMaterials = new HashSet<>();
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Methods
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * This method builds all necessary elements in GUI panel.
+	 */
+	@Override
+	public void build()
+	{
+		PanelBuilder panelBuilder = new PanelBuilder().user(this.user).
+			name(this.user.getTranslation("challenges.gui.admin.manage-blocks"));
+
+		// Create nice border.
+		GuiUtils.fillBorder(panelBuilder);
+
+		panelBuilder.item(3, this.createButton(Button.ADD));
+		panelBuilder.item(5, this.createButton(Button.REMOVE));
+
+		final int MAX_ELEMENTS = 21;
+
+		if (this.pageIndex < 0)
+		{
+			this.pageIndex = this.materialList.size() / MAX_ELEMENTS;
+		}
+		else if (this.pageIndex > (this.materialList.size() / MAX_ELEMENTS))
+		{
+			this.pageIndex = 0;
+		}
+
+		int entitiesIndex = MAX_ELEMENTS * this.pageIndex;
+
+		// I want first row to be only for navigation and return button.
+		int index = 10;
+
+		while (entitiesIndex < ((this.pageIndex + 1) * MAX_ELEMENTS) &&
+			entitiesIndex < this.materialList.size())
+		{
+			if (!panelBuilder.slotOccupied(index))
+			{
+				panelBuilder.item(index, this.createElementButton(this.materialList.get(entitiesIndex++)));
+			}
+
+			index++;
+		}
+
+		// Navigation buttons only if necessary
+		if (this.materialList.size() > MAX_ELEMENTS)
+		{
+			panelBuilder.item(18, this.getButton(CommonButtons.PREVIOUS));
+			panelBuilder.item(26, this.getButton(CommonButtons.NEXT));
+		}
+
+		// Add return button.
+		panelBuilder.item(44, this.returnButton);
+
+		panelBuilder.build();
+	}
+
+
+	/**
+	 * This method creates PanelItem button of requested type.
+	 * @param button Button which must be created.
+	 * @return new PanelItem with requested functionality.
+	 */
+	private PanelItem createButton(Button button)
+	{
+		PanelItemBuilder builder = new PanelItemBuilder();
+
+		switch (button)
+		{
+			case ADD:
+				builder.name(this.user.getTranslation("challenges.gui.button.add"));
+				builder.icon(Material.BUCKET);
+				builder.clickHandler((panel, user1, clickType, slot) -> {
+
+					new SelectBlocksGUI(this.user, new HashSet<>(this.materialList), (status, material) -> {
+						if (status)
+						{
+							this.materialMap.put(material, 1);
+							this.materialList.add(material);
+						}
+
+						this.build();
+					});
+					return true;
+				});
+				break;
+			case REMOVE:
+				builder.name(this.user.getTranslation("challenges.gui.button.remove-selected"));
+				builder.icon(Material.LAVA_BUCKET);
+				builder.clickHandler((panel, user1, clickType, slot) -> {
+					this.materialMap.keySet().removeAll(this.selectedMaterials);
+					this.materialList.removeAll(this.selectedMaterials);
+					this.build();
+					return true;
+				});
+				break;
+		}
+
+		return builder.build();
+	}
+
+
+	/**
+	 * This method creates button for given material.
+	 * @param material material which button must be created.
+	 * @return new Button for material.
+	 */
+	private PanelItem createElementButton(Material material)
+	{
+		return new PanelItemBuilder().
+			name(WordUtils.capitalize(material.name().toLowerCase().replace("_", " "))).
+			icon(GuiUtils.getMaterialItem(material, this.materialMap.get(material))).
+			clickHandler((panel, user1, clickType, slot) -> {
+				// On right click change which entities are selected for deletion.
+				if (clickType.isRightClick())
+				{
+					if (!this.selectedMaterials.add(material))
+					{
+						// Remove material if it is already selected
+						this.selectedMaterials.remove(material);
+					}
+
+					this.build();
+				}
+				else
+				{
+					new NumberGUI(this.user, this.materialMap.get(material), 1, (status, value) -> {
+						if (status)
+						{
+							// Update value only when something changes.
+							this.materialMap.put(material, value);
+						}
+
+						this.build();
+					});
+				}
+				return true;
+			}).
+			glow(this.selectedMaterials.contains(material)).
+			build();
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Enums
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * Functional buttons in current GUI.
+	 */
+	private enum Button
+	{
+		ADD,
+		REMOVE
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Variables
+// ---------------------------------------------------------------------
+
+	/**
+	 * Contains selected materials.
+	 */
+	private Set<Material> selectedMaterials;
+
+	/**
+	 * List of materials to avoid order issues.
+	 */
+	private List<Material> materialList;
+
+	/**
+	 * List of required materials.
+	 */
+	private Map<Material, Integer> materialMap;
+}