KEY CYLINDER DEVICE

A key cylinder device (1) includes a rotor (4) resiliently mounting tumblers (45) that are aligned by insertion of a mechanical key, a rotor case (3) rotatably housing the rotor (2) that is inserted in a direction opposite to an insertion direction of the mechanical key, and a cylindrical sleeve (5) arranged around an outer peripheral surface of the rotor (4) and fixed to an inner surface of the rotor case (3). The sleeve (5) includes a hole (51) that allows the tumblers (45) to be disengaged when the mechanical key is inserted and to be engaged when the mechanical key is extracted.