To make configuration simple and light in weight and to facilitate angle adjustment and attachment to a boot by fixing one side end of binding through the specified number of screws at a set position on the main body of board and fixing the other end through the specified number of screws at an arbitrary position on the main body of board.

A pair of bindings 3x and 3y are attached on an upper face 2U of a main body 2 of board while being lengthwisely separated. One nut is buried at previously set positions Px and Py on the main body 2 of board. The bindings 3x and 3y are composed of main body 9 of binding integrally forming a horizontal attachment base 11 and an upward rising rear stopper part 12 from synthetic resin. A screw inserting hole 13 formed on the rear side of the attachment base part 11 is fixed with the nut 6 by one screw 4. Besides, the front side of the attachment base 11 is fixed by screws more than one or two. When the bindings 3x and 3y are turned and displaced with the screw 4 as a supporting point, angle adjustment and attachment can be facilitated.