PURPOSE: To make lumpy kneaded dough possible to continuously forming to belt-like shape without destroying net-like gluten in the dough by installing a nozzle and a knife shutter synchronously operating with reciprocating cycle of a conveying belt and a piston.

CONSTITUTION: A piston 4 reciprocating in a cylinder chamber 16 having rectangular cross section is installed in the aimed extruder together with a conveying belt conveyer 10 having at least a breadth equivalent to inner breadth of the chamber 16 and continuously driven to extruding direction of the piston 4 in approximately same plane as a guiding face leading to lower edge of opening end of the chamber 16. Then, opening part of the chamber 16 is constructed with a nozzle formed by a pair of auxiliary boss 5 operating to widen or narrow in synchronizing with reciprocating cycle of the piston 4, a hopper 1 having a bottom opening communicating to upper side of the chamber 16 and a knife shutter 3 operating so as to shut the communicating path according to advancing cycle and open according to recessing cycle of the piston 4.