To provide a safety switch in which a safety door cannot be opened unless an open directive is given by a control device after the safety door is closed, in which a lock state is retained even in the case a power supply interception to the control device occurs because of power failure or the like, and in which forced release of the lock cannot be carried out at the normal time except the time of interception of the power supply.

This lock type safety switch is composed of a key member and the switch main body respectively mounted onto a safety fence or the safety door. The key member has a fixed part, and the switch main body has a lock means provided with a fixed member to be engaged with the fixed part of the key member, and a plunger which is capable of moving in a longitudinal direction and pushes the fixed member at one end by a solenoid or a spring, a lock release means which is provided at a regulating part to regulate movement of the plunger of the lock means at one end, which is capable of moving in the longitudinal direction, and goes in the one end direction by a solenoid or the spring, and in which the regulating part is pushed, and a forced release means in which the regulating part is retreated from the plunger of the lock means in such a state that the plunger of the lock means is regulated by the regulating part.