A semiconductor switching element and a semiconductor switching device involving the same which comprise at least one collector region diffused in a semiconductor substrate from its surface, containing a high concentration of impurities having the same type of conductivity as said substrate and displaying a higher degree of said conductivity than said substrate and formed into a fully narrow area, a base region diffused at a space of approximately 50 microns max. from said collector region, as measured from the same surface of said semiconductor substrate as that on which there is formed said collector region, in a manner to make the edge of said base region facing said collector region sufficiently longer than that of said collector region and containing a high concentration of impurities having the same type of conductivity as said semiconductor substrate and displaying a higher degree of said conductivity than said semiconductor substrate and at least one emitter region diffused from the same surface of said semiconductor substrate as that through which the aforesaid two regions are diffused and having an opposite type of conductivity to said semiconductor substrate.