To improve working efficiency of a machining work including attaching/detaching of a plurality of small-sized workpieces to/from a machine tool by providing a technical means capable of holding the plurality of workpieces in a state of the workpieces arranged in parallel by uniform force, regarding a cap fixed to a jaw of the vise.

The gripping cap 3 of the vise is provided with the master cap 6 fixed to the jaw of the vise, a plurality of slave caps 7 arranged side by side to face the master cap 6 in a state of sides brought into sliding contact with each other, a locking tool 11 for locking a lower part of each of the slave caps 7 on the master cap 6 with a prescribed gap, and elastic members 14 and 16 for energizing each of the slave caps 7 in a direction for separating each of the caps 7 from the master cap 6. The gripping cap 3 is used by being made as a pair with the pressing cap 5. The pressing cap 5 is provided with plungers inserted into each of plunger holes provided on a main body 8 fixed to the jaw of the vise, a horizontal hole for communicating bottom parts with each other of the plunger holes, and rolling members filled in a row into the horizontal hole.