PURPOSE: To realize a fine and high-density PROM with high reliability, by stacking alternately a wiring layer of the 1st material which generates heat by electric conduction and another wiring layer of the 2nd material which is fused by the heat of the 1st wiring layer and has a melting point lower than the 1st winding layer.

CONSTITUTION: The 1st wiring layer 30 containing the polycrystal Si of low resistance is formed on an insulated film 20 on a semiconductor substrate 10. Then the 2nd wiring layer 50 which has a melting point lower than the layer 30 is formed on the layer 30 via an insulated film 40. When a program current is supplied to the layer 30 in a program operation mode, the layer 30 functions as a heating element. The heat generated from the layer 30 heats and melts a cross part 90 of the layer 50 via the film 40. Thus the part 90 is disconnected to obtain the infinite electric resistance. As a result, the high density and high reliability can be improved for a PROM element.