This invention provides a DMOS transistor that has a reduced ON resistance and is prevented from deterioration in strength against an electrostatic discharge. An edge portion of a source layer of the DMOS transistor is disposed so as to recede from an inner corner portion of a gate electrode. A silicide layer is structured so as not to extend out of the edge portion of the source layer. That is, although the silicide layer is formed on a surface of the source layer, the silicide layer is not formed on a surface of a portion of a body layer, which is exposed between the source layer and the inner corner portion of the gate electrode. As a result, the strength against the electrostatic discharge can be improved, because an electric current flows almost uniformly through whole of the DMOS transistor without converging.