The switch device includes a control switch that turns on/off an electrical connection between an apparatus and the power supply, a condition judging circuit that judges conditions of driving the control switch, an electric wave reception circuit that receives an electric wave, and a power supply circuit that generates power from the electric wave received by the electric wave reception circuit. An electric wave transmission device that transmits an electric wave for making the switch device operate is arranged in a space, whereby the electric wave can be received by the electric wave reception device in the specific space. The switch device controls the control switch to be turned off/on when the electric wave is received. Alternatively, when the electric wave is not received, the switch device turns on/off the control switch.