Cell collection method

A cell detaching method of detaching cells having been cultured in a culture container containing a liquid culture medium and adhered to an inner surface of the culture container, the method comprising:

• a culturing process of culturing the cells in the container by using the culture medium;
• a culture medium movement process of moving the used culture medium in the culture container to a reservoir after the cells are cultured;
• a detachment liquid supply process of, after the culture medium movement process, supplying a detachment liquid for detaching the cells from the inner surface of the culture container to the culture container;
• and
• a mixing process of, after the detachment liquid supply process, moving a suspension in which at least a part of the detachment liquid and the cells are mixed from the culture container to the reservoir and mixing the suspension and the used culture medium in the reservoir,
• wherein the reservoir includes a first reservoir and a second reservoir different from the first reservoir,
• wherein the culture medium movement process includes:
• a first culture medium movement process of moving a first part of the used culture medium, from the culture container to the first reservoir;
• and
• a second culture medium movement process of moving a second part of the used culture medium different from the first part of the used culture medium, from the culture container to the second reservoir,
• wherein in the mixing process, the suspension in which the at least the part of the detachment liquid and the cells are mixed is moved from the culture container to the first reservoir, and
• wherein after the mixing process, a return process of moving the second part of the used culture medium from the second reservoir to the culture container is performed.