To provide an electric circuit control/protection unit.

A lock hole is formed in a push button; an extension groove is extended in the lock hole; one end of an interlock rod is fitted to the lock hole in an action style; an end of the interlock rod is connected to a contact piece in an action style; the interlock rod is operated and the contact piece is pushed, pulled and made to jump by pressing and rocking the push button; and an ON-state or an OFF-state is formed in an electric circuit. When the push button is located at an electric circuit conducting (ON) position, the extension groove of the lock hole provides a space for free movement for the end of the interlock rod; when the contact piece is deformed by heating and elastically jumps in the opposite direction in current overload, the contact piece pressingly moves the interlock rod; the end of the interlock rod freely moves in the extension groove; and the contact piece smoothly jumps and gets away without being blocked by the push button to form free jumping cut-off (OFF) of the electric circuit and secures safety of power usage.