To provide a plate module fixing structure which can enhance the workability of a plate module, such as a solar cell module.

In a fixing structure 1 of a plate module 2, a male screw portion 51 of a male screw member 50 is screwed into a female screw portion of a female screw member 30 inserted into a sliding groove 21 of a slide support member 20 through a slit 22 of the slide support member 20 and a through hole 41a of an abutting piece 41 of a fixed member 40 which is in abutment with a mounting part 23 of the slide support member 20. The fixed member 40 is screwed to be fixed to the slide support member 20 by the male screw member 50 in such a manner that a head portion 52 of the male screw member 50 is received in a recessed portion 41b of the abutting piece 41 of the fixed member 40, and a side face of the plate module 2 is inserted between the abutting piece 41 of the fixed member 40 and a supporting piece 43.