An insulated gate semiconductor device, which improves high frequency characteristics by reducing the resistance of a path from a gate bonding portion to each gate and eliminating an unbalance in resistances of respective gates, and which obtain a higher output by eliminating a limitation in current capacity due to the thickness of a first metal layer. In this insulated gate semiconductor device, a first aluminum layer is connected in parallel onto a gate electrode made of polycrystalline silicon. The adjacent gates, each having such a double layer structure, extend outside channel regions and are connected to each other. A lead-out electrode of a second aluminum layer is connected to the center of the connection portion of the adjacent gates through an opening portion. A gate bonding portion is provided at the center of the lead-out electrode. Each of source and drain electrodes is also of a double layer structure having the first aluminum layer and the second aluminum layer.