The invention relates to a dispensing cylinder, a large capacity dispensing device, and a method of using a large capacity dispensing device, and aims at providing a dispensing cylinder, a large capacity dispensing device, and a method of using a large capacity dispensing device, with high quantitativity and capable of suppressing the scale of the device and efficiently utilizing working space, despite the relatively large volumes of fluid handled. The construction comprises: a small diameter section, a large diameter section which communicates with the small diameter section and is capable of holding fluids, a sliding section provided in a slidable manner within the large diameter section which enables fluid to be sucked and discharged to and from the large diameter section through the small diameter section, and a connection section which connects the sliding section in a detachable manner to a suction and discharge mechanism which drives the sliding section.