PURPOSE: To surely and firmly hold a shapeless work by providing a fixed flat holding claw and a semi-circular holding claw turnable around an arc surface on at least one of a pair of holding jaws attachable/detachable to/from each other.

CONSTITUTION: A pair of holding jaws 100 attachable/detachable to/from each other are arranged in a vice body, and a flat holding claw 102 having an inclined holding surface 103 and a flat holding surface 104 is fixed to each holding jaw 100. A semi-circular holding claw 101 having a turnable flat surface 105 is rotatably fitted along an arc surface adjacent to the inclined holding surface 103 of the flat holding claw 102. When a rectangular work is held, the work is held between the flat holding claw 102 and the semi-circular holding claw 101, and when a small diameter columnar work is held, it is held by four holding surfaces, i.e., the inclined holding surfaces 103 of the flat holding claw 102 and turnable flat surfaces 105 of the semi-circular holding claw 102. The work can thus be surely and firmly held thereby.