The present invention relates to a dosing mechanism including: a body (2)； and a disposable portion (3) that is removably attached to the body (2), in which the disposable portion (3) includes: a pump that sucks a medicine from a medicine vessel and discharges the medicine to a patient； a suction-side tube (33) that extends from the pump toward the medicine vessel； a discharge-side tube (34) that extends from the pump toward the patient； and a connector (331, 341) that is located at a front end of at least one of the suction-side tube (33) and the discharge-side tube (34), and the body (2) includes a sensor (24) in a position corresponding to the suction-side tube (33) or the discharge-side tube (34) attached to the body (2).
