To provide a center lock that can prevent a wristwatch from coming off.

A center lock comprised of an outside connecting plate 33 attached rotatably to the end of the first band 31, an inside connecting plate 35 connected to the outside connecting plate, and a swinging frame 40 attached ratatbly to the end of the inside connecting plate 35, is formed. A pressing plate 43 is attached to the swinging frame so that the second band 36 may be inserted into a clearance with the bottom plate 38 of the swinging plate, a pressing projection 48 to be brought into pressure contact with the second band 36 by bringing it into pressure contact with the pressing plate 43 is formed at the end of the inside connecting plate 35. A stopping bar 50 that is brought into pressure contact with the pressing projection in a center lock fixing position where the pressing projection presses strongly the pressing plate 43 and prevents the inside connecting plate 35 from rotating beyond the center lock fixing position, is fixed to the swinging frame.