To rapidly mount and remove boots to and from a fastening means by operating laterally a plate having a circular opening for connecting a disk fixedly to a snowboard relative to a counter plate fixed to the bottom part of the boots.

When a locking claw is pulled with a pin by rotating an operating layer 30, pressure is added from the side by the insertion of the end 34 into a seat, and a counter plate 10 is fastened to a protection to eliminate completely a play. The locking claw is thereafter rotated until a claw-shaped part is connected to the lower of a flap 15 to lock the counter plate 10. At the same time a claw-shaped lever connects a tooth 61 of a locking lever 60 connected to the connecting part of a connection part 50 to a bent part to provide further pressure. Further, the rotation of the locking lever 60 causes the rotation of a safety lever 70, and a tooth-shaped part 75 is combined with the connection part 76 of the safety lever 70 to prevent accidental opening.