A centrifugal piston according to an embodiment comprises: a piston body defining a path which extends from the front of the piston to the rear of the piston, and through which substances at the front of the piston can move to the rear of the piston； and a valve disposed on the path and configured to selectively open or block the path, wherein, during centrifugation in which centrifugal force acts on the piston, the substances at the front of the piston are centrifuged while the valve is blocking the path, and, when an external force is applied to the piston while the centrifugal force does not act on the piston, the valve moves freely relative to the piston body, and when the valve opens the path, at least a portion of the substances at the front of the piston can move to the rear of the piston.
