A clamping device that is always capable of clamping a flexible tube in a good manner and assuredly closing the flexible tube without a large clamping force. A clamping device includes a holding member that holds a flexible tube in which a fluid is allowed to flow, and a clamping member that clamps and closes a clamping portion of the flexible tube that is held by the holding member. The clamping device further includes a heating device that heats the clamping portion of the flexible tube.
