A color cathode ray tube includes a generally rectangular shadow mask structure in which a skirt portion of a shadow mask is secured to a support frame. The shadow mask is formed by an apertured portion having a large number of electron beam transmission apertures, an imperforate portion disposed around the entire periphery of the apertured portion, a skirt portion being bent back and drooping from the entire periphery of the imperforate portion, and a support frame including a rectangular frame portion. The skirt portion of the shadow mask is secured to the inside of the rectangular frame portion, and a bent portion of the shadow mask, which defines a transitional region between the imperforate portion, and the skirt portion is formed in a shape where long sides are recessed inwardly and ends of the long sides of the skirt portion come into contact with the frame portion.