To achieve an abrasive finishing of glinding surfaces of boards smoothly and accurately in the tuning up work while enhancing edging operability by facilitating a forward inclined attitude taken by a skier during the gliding period.

The thickness dimension of a board body 1 integrally formed out of ski component members is gradually increased toward the side of the rear ground contact point B of skis with the maximum height T of 1-10mm in a range F of a shoes binding mounting position for tows and heels almost at the central part along the length of the skis between both front and rear ground contact points A and B of the skis. The thickness dimension is gradually decreased over the length range L3 of 50-200mm to the side of the rear ground contact point B from the maximum part of the thickness.