A library device includes: a storage shelf including storage units aligned in a plurality of columns; and a conveying robot that grasps and conveys cartridges stored in the storage units, wherein the conveying robot includes: a base board located to face the plurality of columns, one end of the base board being supported movably up and down by a first support post, and another end of the base board being supported movably up and down by a second support post; a movable unit including a grasping unit grasping the cartridges stored in the storage units and moving on the base board; an inclination measuring unit measuring an inclination of the movable unit; and an inclination correction unit adjusting heights of both ends of the base board according to an inclination value of the movable unit measured by the inclination measuring unit and correcting the inclination of the movable unit.