PURPOSE: To improve the ultraviolet shielding property of the title circuit board by a method wherein at least one sheet of a prepreg obtainable by impregnating a varnish, in which a fluorescent paint shown by formula I to a thermosetting resin solid content is blended in a specified ratio, in a glass woven fabric or a glass nonwoven fablic is used.

CONSTITUTION: Glass fiber base materials, such as glass woven fabric or glass nonwoven fabric base materials, which are impregnated a thermosetting resin therein and are dried, are laminated and molded. At least one sheet of a prepreg obtainable by impregnating a varnish, in which a fluorescent dye consisting of (1-(phenyl0-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline) shown by the formula to a resin solid content is blended at 0.01 to 1.0wt.%, in a glass woven fabric or a glass nonwoven fabric is used. the fluorescent dye shown by the formula utilizes a fluorescence property of a stilbene structure, absorbs ultraviolet rays and light at visible parts and moreover, is applied a coloring power and a visibility, which are required as a dye, by introducing a pyrazoline ring, which is one part of an azo dye, in it to shield light at a long wavelength region and to improve the heat resistance of the title circuit board.