CIRCUIT BREAKER

The present invention provides a circuit breaker which includes: a lower base body on which a plurality of receiving spaces are formed in parallel to receive a plurality of phase detecting units, wherein the terminal unit of each phase detecting unit protrudes to the rear end of the lower base body; an upper base body which includes a plurality of cover spaces which are combined with the upper end of the upper base body and covers the upper side of each receiving space; a plurality of phase detecting device assembling units which are electrically connected to the terminal unit of each phase detecting unit and switch a circuit when an abnormal current is generated on each phase circuit; and a switching device which is rotationally installed on the upper end of the upper base body and includes a lever which moves to a trip position by receiving a signal about a circuit switching operation from the phase detecting device assembling units.