To provide a plate material conveyance device by which plate materials of various sizes and shapes are stably transferred and interference by a suction-pads arrangement body is prevented.

A plate material conveyance device is provided with a suction-pads arrangement body 36 on which a plurality of suction-pads 35 for sucking a plate surface are arranged. The suction-pads arrangement body 36 comprises a pads-loading frame 33 on which a plurality of suction pads 35 are mounted. The pads-loading frame 33 is composed of a main frame 33a, and a pair of retractable frames 33b and 33c which are provided on both right and left sides of the main frame 33a and expand and contract in the right and left direction to the main frame 33a. The suction-pads 35 are mounted on the main frame 33a and a retractable frame 3b, and the distance between the suction-pads 35 of the suction-pads arrangement body 36 can be changed freely according to the size or shape of a plate material W.