A molded case circuit breaker comprising: a case configured to accommodate an element for trip; an upper cover detachably attached to the case; a dial configured to include a fixing plate, which is provided to protrude along an outer circumference surface thereof, and a first stopper disposed under the fixing plate; a crossbar moved by the dial; a first dial fitting hole provided in the upper cover for the dial to be fitted into the first dial fitting hole; a dial rotation adjusting unit provided in the first dial fitting hole and fitted between the fixing plate and the first stopper to guide a rotation of the dial, the dial rotation adjusting unit including a plurality of fitting grooves arranged at certain intervals; a moving bar disposed under the first stopper to move the crossbar according to the rotation of the dial; and a moving bar fitting hole provided in the first dial fitting hole for the moving bar to be fitted into the moving bar fitting hole as one body, wherein the first stopper is fitted into and fixed to the plurality of fitting grooves according to the rotation of the dial, wherein the dial rotation adjusting unit comprises a rotation guide plate provided to protrude inside the upper cover and fitted between the fixing plate and the first stopper to guide the rotation of the dial, wherein the plurality of fitting grooves are provided in the rotation guide plate to be spaced apart from each other by a certain interval, and characterized in that a first stopper moving space is provided between the first stopper and the moving bar, wherein when the dial rotates, the first stopper is bent in a direction toward the moving bar. a case configured to accommodate an element for trip; an upper cover detachably attached to the case; a dial configured to include a fixing plate, which is provided to protrude along an outer circumference surface thereof, and a first stopper disposed under the fixing plate; a crossbar moved by the dial; a first dial fitting hole provided in the upper cover for the dial to be fitted into the first dial fitting hole; a dial rotation adjusting unit provided in the first dial fitting hole and fitted between the fixing plate and the first stopper to guide a rotation of the dial, the dial rotation adjusting unit including a plurality of fitting grooves arranged at certain intervals; a moving bar disposed under the first stopper to move the crossbar according to the rotation of the dial; and a moving bar fitting hole provided in the first dial fitting hole for the moving bar to be fitted into the moving bar fitting hole as one body, wherein the first stopper is fitted into and fixed to the plurality of fitting grooves according to the rotation of the dial, wherein the dial rotation adjusting unit comprises a rotation guide plate provided to protrude inside the upper cover and fitted between the fixing plate and the first stopper to guide the rotation of the dial, wherein the plurality of fitting grooves are provided in the rotation guide plate to be spaced apart from each other by a certain interval, and characterized in that a first stopper moving space is provided between the first stopper and the moving bar, wherein when the dial rotates, the first stopper is bent in a direction toward the moving bar.