PURPOSE: A circuit breaker for a ventilator is provided to prevent outside air flowing in into the inner side of a ventilator by closing an exhaust path of the ventilator when the ventilator stops because a circuit breaker for the ventilator is installed in a side of the ventilator. CONSTITUTION: A circuit breaker for a ventilator comprises a housing and a frame(2). A long groove where the frame is joined in an upper side of the housing and a supplying hole receiving air from a ventilator is formed in a side of an area adjacent to the long groove and a discharge hole discharging the air discharged from the ventilator to outside is formed in the other side of the supplying hole. The frame is composed of a first frame(21) and a second frame(22).
