Abstract: The object of this invention is to provide a method of manufacturing diodes, said method being a method of manufacturing semiconductor devices whereby an insulating film as the upper layer of the diode can be removed without causing film peeling or leakage. A photodiode is formed by forming a semiconductor layer of a second conduction type 12 upon the surface layer of a semiconductor layer of a first conduction type 11, and next forming a removable mask layer 30 which has etching selectivity with respect to the semiconductor layer of a second conduction type, or alternately, forming an anti-reflection film AR upon the top layer of the semiconductor layer of a second conduction type and then forming a removable mask layer which has etching selectivity with respect to the anti-reflection film. Next, a removable insulating layer I which has etching selectivity with respect to the mask layer is formed upon the top layer of the mask layer.