PURPOSE: To obtain a device for producing a regenerated synthetic resin material stock which is to be regenerated as a pellet-form synthetic resin material from recovered expanded polystyrene products generally used for a package and the like.

CONSTITUTION: A title device is a compact device provided with a hopper 1 for supplying the chips of expanded polystyrene products which have been recovered; a compression molding chamber 2 connected to the lower part of the hopper 1 so as to extend in a horizontal direction; a pressing plate 4 provided in the compression molding chamber 2 for crushing the chips against a gate 3 which closes the open top end of the chamber 2; an encoder 6 provided on the pressing plate 4 for detecting the travel amount of the pressing plate 4; and a controller 7 for controlling the movement of the pressing plate 4 in accordance with a signal input from the encoder 6.