The present invention relates to a two-stage lock structure of an ATM that can prevent an operator from being injured during the removal of a currency note jam. The two-stage lock structure includes: a temporary stack to be moved upward by rotating about a temporary stack hinge shaft to open a conveyance path when a currency note jam occurs; a protruding member protruding from one surface of the temporary stack; a stopper that includes a first aperture and a second aperture into which the protruding member is inserted to hold the temporary stack rotated about a hinge shaft, and a slide aperture in which the protruding member slides and is rotated about a stopper hinge shaft; and an elastic member provided to pull the stopper in a direction where the protruding member is held in the first or second aperture.