Abstract: After forming a phosphor film on an inner face of a front panel, light exposure is performed with respect to the phosphor film by irradiating light from an exposure light source onto the phosphor film through an exposure lens. The exposure lens has a concave incidence surface on which light from the exposure light source is incident, and the incidence surface has an average radius of curvature of 100 mm to 500 mm. Thus, light to which peripheral portions are exposed can have a smaller incident angle with respect to the incidence surface of the exposure lens, thereby allowing the reflectance of the light to be decreased. As a result, even in light exposure with respect to a phosphor film of a color picture tube with a wide deflection angle, an amount of light for the light exposure can be secured in the peripheral portions.