PURPOSE: To make it possible to treat a large amount of cell suspension in a size of cell fusion chamber to be placed on a stage of microscope, by piling thin plate electrodes through insulating plates to give an aggregate, attaching the aggregate to the inside of a cover of a container with a spring hanging tool and making the tips of the thin plate electrodes be pushed against the bottom of the container.

CONSTITUTION: Thin plate electrodes 2-1, 2-2, 2-3... are sandwiched between transparent insulating plates, holes are bored through the electrodes 2 and the insulating plates 4 and closed with insulating materials 6. An aggregate of the thin plate electrodes is attached to an inner face of a cover 16 by spring hanging tools 20. A common connecting material 8 is passed through protrusions of the thin plate electrodes in odd numbers and used as a negative side electrode. A common connecting material 10 is passed through protrusions of the thin plate electrodes in even numbers and used as a positive side electrode. Both the connecting materials are connected to terminals 12... of the cover, respectively. When a container 24 is covered with the cover 16, the thin plate electrodes are pushed against the bottom of the container by the spring of the hanging tools 8.