A lateral conductivity modulated MOSFET comprises a semiconductor wafer, a first-conductivity type base layer selectively formed in a surface region of the semiconductor wafer, a second-conductivity type source layer selectively formed in a surface region of the first-conductivity type base layer, a second-conductivity type base layer selectively formed in the semiconductor wafer, a first-conductivity type drain layer formed in a surface region of the second-conductivity type base layer, a gate insulation film formed on that surface portion of the first-conductivity type base layer which is sandwiched between the source layer and the second-conductivity type base layer, a gate electrode formed on the gate insulation film, a source electrode in contact with both the source layer and the first-conductivity type base layer, and a drain electrode in contact with the drain layer. A second-conductivity type cathode layer is formed in a surface region of the semiconductor wafer in such a manner that it is located adjacent to the second-conductivity type base layer. A cathode electrode is in contact with the cathode layer and is kept at the same potential level as that of the drain electrode.