PURPOSE: To enable the sanitary and rapid cooking of a just prepared hamburger by cooking a putty discharged from a putty stock in a sandwiched and heated state with the cooker.

CONSTITUTION: Pieces of a putty (HP), together with a putty capsule 14, are fed from a putty capsule feeder 1 one by one to a thermal cooker 2. When the putty capsule is accurately arranged at a heating position with a feeding device 15, an electromagnetic cooker (2a) is lowered to cook each piece of the putty in a sandwiched and heated state with the electromagnetic cookers (2a) and (2b). The resultant hamburger in a packaged state is fed through a transferring device 10, a packaging device 11 and a discharging device.