PURPOSE: To provide the title unit so designed that each pearl chain of two kinds of cells is formed with specific plural pairs of the first electrodes and the both pearl chains are brought into contact with each other through the second electrodes followed by fusion with a direct current high voltage pulse, thereby raising the production efficiency of heterokaryons.

CONSTITUTION: A cell suspension containing cells A is put in a space surrounded by the following: (A) a bottom plate made of transparent glass 1, (B) plural pairs of thin lamellar first electrodes 2a-1W2a-4, 2b-1W2b-4, 3a-1W3a-4, 3b-1W3b-4 facing at the edge surface each other on the plate A, (C) insulators 4 arranged and bonded between the electrodes B and (D) the second electrodes 5a, 5b arranged facing each other in the direction rectangular to the electrodes A. After the precipitation of the cells A, a high frequency voltage is applied on the respective pairs of electrodes 2a-1W2b-4 among the first electrodes to form pearl chains 6-1W6-4 of the cell A. Thence, a second high frequency voltage differing in phase by 180° from that of the above voltage is applied on the residual first electrodes 3a-1W3b-4 to form pearl chains 7-1W7-4 of the cell B from a second cell suspension containing the cells B. Thence, a high frequency voltage is applied between the second electrodes 5a, 5b to cause electrophoresis to effect contact of the cells A and B with each other, thus accomplishing the objective cell fusion with a direct current high voltage pulse.