A mask supported at a frame when a tensile force is applied in a first direction is provided. The mask includes a mask main body in a band shape extended in the first direction, and a plurality of pattern openings formed in the mask main body. the mask main body has ends supported by the frame, and the pattern opening are arranged in the first direction. The mask further includes a dummy opening provided between the pattern openings and one of the ends of the mask main body. The dummy opening has a form that is different from forms of the pattern openings.