A circuit breaker having a cradle, the circuit breaker comprises: an upper shutter and a lower shutter configured to open and close terminals of the cradle; an upper shutter operation link having one end connected to the upper shutter and another end rotatably coupled to a pivot; a lower shutter operation link having one end connected to the lower shutter and another end rotatably coupled to the pivot; and a shutter safety device comprising a coupling unit fixedly-coupled to the pivot, a rotation unit rotatably coupled to the coupling unit, and a link fixing unit provided at one end of the rotation unit, wherein the link fixing unit is to restrict rotation of the upper shutter operation link and the lower shutter operation link in a contacting manner.