A cell sorting apparatus includes an extracorporeal circulation system 10 for sampling blood from a subject and circulating the blood outside a body a cell measuring section 20 for supplying measurement light to cells contained in the blood to optically measure cell information on the physical quantity relating to the volume of the cell itself or a nucleus of the cell and a cell separating section 30 for separating cells with reference to the cell information measured. The cell separating section 30 separates cells, based on the cell information measured by the cell measuring section 20 and a sorting condition set for sorting a specific type of cell such as a cancer cell, the cells satisfying the sorting condition, and returns the other cells into the body via the extracorporeal circulation system 10. Thus, a cell sorting apparatus can be realized which is capable of suitably sorting a target cell from the cells in blood.
