PURPOSE:To make possible the resuspension of separated and concentrated cells by allowing a septor and a rotor to rotate at different angular speeds in such a state that part of the septor and rotor are immersed in a liquid in the rotor, when the recovered cells sticking to the inner wall of the rotor are resuspended in a medium liquid. CONSTITUTION:A culture liquid containing cells is introduced into a rotor 12 from a culture tank through a flexible pipe 12, a lubrication part 61 and a tubular element 18 prior to centrifugal separation. Then a septor 20 at the lower end of the tubular element 18 is rotated in the same direction and at the same speed as the rotor 21 in such a state that the septor is junctioned to a clutch section. After stopping rotation, a supernatant is discharged through the tubular element 18. Next, a liquid medium is introduced into a rotor chamber 21, and the tubular element 18 is lifted up to such an extent that the entire septor 20 does not rise above a liquid level. After this, the tubular element 18 is fixed with the clutch section 62 cut off and the rotor 21 is reversed to allow the cells sticking to the inner wall of the rotor to be suspended in the liquid medium. In this way, the rotor is permitted to resuspend the separated and concentrated cells in the medium liquid, although the rotor chamber is pressure- resistant and hermetically sealed.