An apparatus for retracting and extending a main body of a circuit breaker includes: a conveying module for retracting or extending the main body into or from a distribution box of the circuit breaker; a lever module including a lever selectively switching between a first state and a second state, where the lever module allows movement of the conveying module when the lever is in the first state, and disallows movement of the conveying module when the lever is in the second state; and an interlock module configured to allow the lever to switch to the first state only when a predetermined external input is applied to the interlock module.