To provide an assemblable/disassemblable locking device which enables the replacement of a component member.

This locking device is equipped with a lock body 100, a shaft member 300 which is supported on the lock body, a plurality of dial rings 200 which are rotated on the shaft member as a rotating shaft, and a long locking member 400 which is directly locked by the plurality of dial rings. The lock body comprises main body-side shaft holes 102a, 102b, 102c and 102d into which the shaft member is to be inserted from the outside, and a band mounting hole 101 and a dial mounting part 105, into which the locking member is to be inserted. The shaft member has a shaft-side band groove 302 into which the locking member is to be inserted. A lock body-side band groove 104, which is provided in the main body-side shaft hole, is formed in a position to form one passage along with the shaft-side band groove. At least a part of the band mounting hole is formed in a direction different from the direction of the insertion/extraction of the shaft member with respect to the lock body.