A panel for a flat screen type CRT includes an internal curvature portion wherein a screen effective surface is formed, and a skirt portion extended rearwardly from an edge of the internal curvature portion. Where Rs is the radius of curvature at an inner side of a corner of a seal edge portion in the skirt portion and Rx, Ry, and Rd are respectively the radii of blend curvature of a long-side portion, a short-side portion and a corner portion in a part where the internal curvature portion and skirt portion meet, the relations 0.4