facing surface areas of the electrodes as known from the formula 10 with d between the electrode gaps being constant the larger the applied frequency f the smaller the impedance specifically applying high frequency decreases the resistance between the electrodes causing a larger current to flow this elevates the medium temperature causing the environment appropriate for cell culture to be deteriorated or a current control system to be complicated in addition considering the technique for achieving a high frequency apparatus to gain a practical dielectrophoretic force the applied frequency is preferably equal to or lower than 10 mhz however with a lower applied frequency electrolysis of water occurs readily accordingly the lower limit is preferably approx 100 hz with respect to the fourth embodiment another cell culture vessel of the present invention is explained by reference to fig1 and 13 in the fourth embodiment an expansion mechanism 3 a shown in fig1 and a side electrode 3 b shown in fig1 are the same as those in the first embodiment hereinafter the same signs are assigned to the same parts as those described with respect to the first embodiment to omit duplicated explanation and only different parts will be explained in the cell culture vessel configured as shown in fig1 to detach the cultured and grown cell the upper electrode 3 is caused to come into contact with the top surface of the.