PURPOSE: To provide a method and a device for monitoring an abnormality of a switch gear capable of discovering an electrically conductive body at an abnormal temperature even in a place of the inner part of switch gear, easily specifying the electrically conductive body at an abnormal temperature, and simple and inexpensive in constitution.

CONSTITUTION: An abnormal temperature display device 18 provided in the vicinity of an electrically conductive body 19 emits the light at the abnormal temperature exceeding a set temperature value of the electrically conductive body 19 such as a main circuit equipment, a conductive part, and a main circuit conductive body stored inside a switch gear. The emitted light is received by an optical fiber 28 and transmitted, the transmitted light is received by a light receiving element 29 to be transduced into the electrical signal, and a switch 32 of a relay 31 is closed by the electric signal.