To provide a low-current motor protecting apparatus formed with a switch chamber, and having an oblong metal housing formed with an opening end.

The housing has an opposite flange laterally extending from the opening end. Part of spaced lid (18a, 18b, 18a', 18b') is located on the flange by a gasket (16) located between the housing and the part of the lid, having a central opening and electrically insulating, and clamped to the flange. The part of the lid is maintained at a correct location by spring clips (22, 22') attached to the lid, and formed with a recessed ceramic heater sheet disposed in the switch chamber having a contact shelf (18f) with a space for accommodating a ceramic heater (20) receiving a supplied contact force.