Disclosed is an air circuit breaker having an insertion/withdrawal linkage type arc cover, the circuit breaker having an arc cover coming into close contact with an arc chute when a main body is inserted into a cradle, thereby preventing a secondary shorting accident of a terminal. The air circuit breaker according to one aspect of the present disclosure comprises: a main body having a plurality of contacts and a plurality of terminals; a cradle into/from which the main body is inserted/withdrawn, and which includes a plurality of terminals correspondingly connected to the plurality of terminals of the main body; a control module which is raised on the cradle, and which is coupled to a coupling module provided at the main body during lowering, so as to electrically connect the main body to the cradle; and an insertion/withdrawal linkage type arc cover which is provided at the cradle so as to be raised together with the control module, and which is lowered when the main body is coupled to the cradle, so as to come into close contact with the upper part of an arc extinguishing part of the main body and cover same.