A semiconductor layer has a first layer of first conductive type, a second layer of second conductive type, and a third layer. The third layer has a first region of first conductive type, and a second region of second conductive type. A second electrode is in contact with each of the first and second regions. A trench is formed on the semiconductor layer at a surface opposite to its surface facing a first electrode. A gate electrode is embedded in the trench with a gate insulating film interposed therebetween. The gate electrode includes a first portion projecting into the first layer through the first region and the second layer, a second portion projecting into the first layer through the second region and the second layer. The second portion projects into the first layer deeper than a depth in which the first portion projects into the first layer.