To solve the problems with snowboards of the prior art that connecting angles for both legs are limited by the width of the snowboard, that an effective edge length is too short, and that localized load causes instability, and to make full use of the performance of the snowboard.

Tune-up parts 2, 3 having both movable leg connecting positions 2 vertically spaced by a predetermined clearance from the upper surface of a snowboard 1 so as not to make direct contact with the upper surface of the snowboard 1, and having connecting portions 3 with the snowboard 1 such that load can be concentrated on a certain lower position between both leg connecting positions 2, are attached to the upper surface of the snowboard 1.