To provide a hook that can be installed on any kind of wall, post, or the like, includes a plurality of catching portions, and has a sufficient hanging strength.

The hook 10 includes: a base board 14 secured on a wall, post 20, or the like by means of a plurality of screws 16 and has a narrow-width portion 14a on a side in close contact with the wall, post 20, or the like and has a wide-width portion 14b further away from the side of the wall, post 20, or the like than the narrow-width portion 14a; a hook base 11 provided with a groove 11a with which the base board 14 is to be engaged; and a projecting portion 12 having a plurality of catching portions provided on the surface of the hook base 11; and the plurality of catching portions 13. The groove 11a is provided on the rear face side of the hook base 11 and extends from one to the other end face of the hook base 11, with a wide-width portion 11a2 having the largest width of the groove 11a being on the bottom side of the groove 11a, not on the opening side.