To provide an interlock device which cuts off a power source breaker connected to a machine by a perceived signal in the absence of a hand-operated fire extinguisher.

A detecting means 20 for perceiving the empty wt. or the existence of a hand-operated fire extinguisher 10 is provided to the hand-operated fire extinguisher 10 arranged on a machine 1 or its surroundings and the detecting means is an interlock device 100 for the hand-operated fire extinguisher for a machine which cuts off a power source breaker 40 connected to a machine by a perceived signal 30 in the absence of a hand-operated fire extinguisher. It is possible thereby to cut off a power source breaker connected to a machine by a perceived signal in the absence of a hand-operated fire extinguisher.