To easily make the foot releasable from a snowboard in the case where one foot needs to be released at the time of moving in a flat place.

The binder is constituted of a claw catch part 3 on both sides of a boot holder A, with a binding B installed in the left and right that is provided with a claw 1 for fixing the catch 3 and a claw 2 with a locking mechanism C. Instead of attaching the boot holder A directly to a snowboard, the binding B is first mounted on the snowboard, and making the binding receive the claw catch part 3 on the boot holder A, and making one foot freely releasable from the snowboard.