PURPOSE: To eliminate pipetting operation and to facilitate automatic operation of the titled chamber, by using a chamber provided with a pair of oppositely arranged electrodes and having a through-hole, attaching a tip of a syringe to the chamber via an opening and attaching a tube via the other opening.

CONSTITUTION: A chamber 2 contains a pair of oppositely arranged electrodes 4, 6 and a space for holding a cell suspension is formed between said electrodes 4, 6. The chamber is provided with a through-hole extending through the above space. The tip of a syringe 12 is detachably fitted to one of the openings of the chamber and a tube 16 is detachably fitted to the other opening of the chamber 2. Pipetting operation can be eliminated and the labor-saving automation can be achieved by this construction.