The present disclosure discloses an electrical switchgear configured to control an electro-magnet by using the electro-magnet, a critical temperature device, and an electro-magnet control unit without using a bimetal and a mechanical contact. The electro-magnet switches power applied through a power line in response to a flow of control current to a power device connected to a load side. In a critical temperature device, an output current value varies when a temperature of a heating wire, which is connected to the power line, exceeds a critical temperature by supply current flowing to the power device. An electro-magnet control unit, which is realizable with an SCR, allows a flow of control current of the electro-magnet to be generated or cut off in response to the output current value of the critical temperature device.