Disclosed is a switch device including a first terminal, a second terminal, a third terminal, a switch element disposed between the first terminal and the second terminal, a control line that reaches a control end of the switch element from the third terminal, a first circuit block that is disposed on the control line and is configured to drive the switch element according to a control signal supplied to the third terminal, at least one second circuit block, each second circuit block being connected to a corresponding one of branch power supply lines that branch from the control line, a first resistor disposed between the third terminal and the first circuit block, and at least one second resistor, each second resistor being disposed on a corresponding one of the branch power supply lines.