An unlocking lever device includes: a lever member which is operated to rotate to allow a locking mechanism to perform an unlocking operation; a sign member which is stored in a storage recessed portion provided in the lever member; a bias member which biases the sign member in a direction of protrusion from the storage recessed portion; and an inclined surface which regulates the protrusion of the sign member from the storage recessed portion in accordance with a position of rotation of the lever member by being abut against the sign member, and generates a bias force which allows the lever member to rotate.