an excitation unit configured to apply a magnetic flux to a wire rope that is an inspection target;

a detection unit configured to detect a magnetic flux of the wire rope to which the magnetic flux has been applied by the excitation unit;

a detachable unit configured to be detachably mounted on a stationary unit fixed in proximity to the wire rope, the detachable unit being provided with at least the detection unit; and

a positioning mechanism configured to position the detachable unit with respect to the stationary unit such that the detection unit is arranged at a predetermined position with reference to the wire rope,

wherein the excitation unit is arranged at the detachable unit together with the detection unit, and

wherein the stationary unit includes a magnetic field application unit for aligning a magnetization direction of the wire rope by applying a magnetic field in advance with respect to the wire rope.