PURPOSE: To produce a stamp molding sheet without using expensive complicated equipment by passing reinforcing fibers and a thermoplastic resin through a die having a taper under heating and drawing out the same by a pressing and cooling taking-over device.

CONSTITUTION: A thermoplastic resin is superposed on reinforcing fibers 5 such as a glass fiber mat in a film form to be passed through a heated die 1 having a taper to impregnate the reinforcing fibers 5 with the thermoplastic resin. The sheet 10 drawn out of the die 1 is passed through a taking-over device 11 having pressing and cooling functions to be pulled. The thermoplastic resin may be scattered over mat like reinforcing fibers in a powdery, granular or fibrous form or, when the mat like reinforcing fibers are produced, a thermoplastic resin powder can be allowed to simultaneously fall.