A light guide part (20) is provided along a Z-axis on a side surface of a case (2) of a relay (1). The light guide part is a thick portion formed of a material forming the side surface of the case, and is structurally integral with the other parts of the case. Also, a light emitting device which emits light in response to application of a voltage to coil terminals (41) is provided within the relay (1) (case). A reflection surface (201) which reflects illuminating light emitted from the light emitting device in a (+Y) direction in a (+Z) direction is placed at a lower end of the light guide part. Illuminating light reflected by the reflection surface is guided to a display surface (200) placed at an upper end of the light guide part, to illuminate the display surface.