Abstract: Even though the shape and size of an aluminum wheel to be chucked for machining is changed, it is possible to easily deal with this situation and to simply chuck the same. In a finger chuck which finger levers 5 are swingably mounted in the radius direction via fulcrum point parts 8 installed at adequately spaced positions in the circumferential direction of the outer circumference of a chuck body, the front end face part of the chuck body front part, which constitutes the front portion of said fulcrum point parts, is eliminated, a plurality of front end face parts 12 which are intended to be selectively replaced and mounted at said eliminated portion are formed integral with each other, and at this time said plurality of front end face parts are provided with a clamp seat 14 and a centering member 23 so that each of said front end face parts can be applied to specified kinds of different workpieces w.