To provide a masking material for coating which protects an aperture part or recessed part and its surroundings surely from coating.

The masking material 1 consists of one or more of insertion parts 2 and a flange 3. The insertion parts 2 are inserted into the aperture part H and the recessed part. The surroundings S of the aperture part H or recessed part are covered with the flange part 3, however, the gap d is arranged between the flange 3 and the surroundings of the aperture part H or recessed part by forming two or more of convex parts 4 with the height of 0.1 mm-1.0 mm on the back surface of the flange 3 so that the coating P does not penetrate into the gap d.