A mask includes a protruding portion provided with a deposition hole formed therethrough and including an upper surface, a lower surface facing the upper surface, and a side surface disposed between the upper surface and the lower surface and inclined at an angle with respect to the lower surface, a peripheral portion including a first surface extending from the upper surface, a second surface facing the first surface and having a step difference with respect to the lower surface of the protruding portion, and a coating layer disposed on the protruding portion. The protruding portion includes at least one of a protrusion protruded from the side surface of the protruding portion and a groove formed by removing at least a portion of the protruding portion from the side surface of the protruding portion, and the coating layer covers at least one of the protrusion and the groove.