To enable a binding to be promptly and safely attached in such a manner that the angle can be changed.

A base plate 2 fixed on a snow board and a rotary plate 4 for attaching a binding, whose angle can be changed are formed. A few fixing members 7 are arranged to elevate fixing pins so as to be selectively inserted or detached into/from retaining holes of the base plate 2, thereby fixing the rotary plate 4 at an optional angle. An operation lever 75 for releasing the fixing members 7 from the fixing positions is displaced in the direction which crosses an elevating direction of the fixing pins 75 so as to be locked at the fixing positions. A circular projection of a hold plate 3 is fit into a circular recessed part of the base plate 2 and a circular through hole 32 of the rotary plate 4, thereby arranging the rotary plate 4 either to be rotatable or fixed.