the arrow 414 a shown in the figure the sliding mechanism 414 can be realized by converting the rotation of the motor into linear motion with a rack or a cam since the position of the culture vessel 110 120 alters by the sliding mechanism 414 the connecting tube connected to the culture vessel 110 120 is arranged to have enough length to maintain the connection even when the position of the culture vessel 110 120 changes the magnetic force regulating unit 407 can get closer to or away from the culture vessel 110 120 along a guide 407 b with a magnetic force regulating unit moving mechanism 407 c when the magnetic force regulating unit 407 gets closer to the bottom surface of the culture vessel 110 120 the magnetic force of the magnets 407 a can concentrate and fix adsorb the magnetic particles and the cells contained in the culture solution in the culture vessel 110 120 on the inner bottom surface of the culture vessel 110 120 when the magnetic force regulating unit 407 gets away from the bottom surface of the culture vessel 110 120 the magnetic force of the magnets 407 a no longer has the effect inside the culture vessel 110 120 and thus the magnetic particles and the cells move away from the inner bottom surface of the culture vessel 110 120 and disperse as shown in fig3 a plurality of permanent magnets 407 a are arranged in a matrix i e vertically and horizontally arrayed at regular intervals in the magnetic force regulating unit 407 each of the permanent magnets 407 a included in this array can concentrate and fix the magnetic particles and the cells contained.