A power MOSFET for a high frequency amplification element having good output power characteristics and high frequency characteristics is described. In the power MOSFET, a shield conductive film electrically connected to via an insulating film is arranged over a drain-offset semiconductor region. A wiring for a drain electrode is so arranged as to extent in parallel to the shield conductive film at one end side of the shield conductive film. On the other hand, a wiring for the gate electrode, a wiring for a source electrode and a gate shunt wiring are arranged in this order to extend in parallel to each other at the other end side of the shield conductive film. The shield conductive film is so formed that the thickness thereof is smaller than that of the wiring for the gate electrode. In this way, the input and output capacitances of the MOSFET can be decreased.