In a shadow mask 21, a large number of slots 23 are made in a mask body 22 in the horizontal direction X and in the vertical direction Y. Each slot 23 has a roughly rectangular backside opening 33, a roughly rectangular front-side opening 32, and a through-hole 31 that connects these two openings 33, 32. Of the multiple slots 23 made in the mask body 22, the slots 23 situated at least in those areas of the mask body 22 that are surrounded by a horizontal axis 24 and two diagonal axes 26, 27 that pass through the center point 28 of the mask body 22 have such front-side openings 32 that a pair of the upper and lower short sides 32c, 32d of the rectangular outline of the front-side opening 32 of each slot 23 are inclined, relative to the horizontal axis 24, along the radiate line 61 radiating from the center point 28 of the mask body 22 toward the slot 23. The angle of inclination .beta. of the short sides 32c, 32d is preferably in the range of a .alpha..+-.10.degree., where .alpha. is the angle between the radiate line 61 radiating from the center point 28 of the mask body toward the slot 23 and the horizontal axis 24.