PURPOSE: To improve the homogeneity and intensity of a planar light source panel by providing a white or silver belt-shaped edge section reflecting layer on the surface edge section of a planar light source panel body on the side not faced to a light source.

CONSTITUTION: A film holder 17 is integrally molded with a flat base 18 with a rear film reflecting layer 24 on the bottom wall face and erect pieces 19... erected with a reverse L-shaped cross section on three sides of the base 18 not faced to a light source, horizontal rear faces of the erect pieces 19 are arranged along the longitudinal direction on the surface edge section of a resin substrate on the side not faced to the light source to form a belt-shaped edge section reflecting layer 21, and the rear faces of the erect pieces 19 are formed into an end face reflecting layer 22 for the end face on the side not faced to the light source. Homogeneity is secured even when a planar light source panel body is made thin.