An infusion pump includes a pump body for holding a roller clamp 7, and a roller movement mechanism 3 for moving a roller 72 of the roller clamp 7 and operating in coordination with manipulation of a door lock mechanism. When the door lock mechanism is in an unlocked state, an infusion tube T is blocked by the roller clamp 72. This configuration reliably prevents free flow even if a door is not closed completely or if the door is accidentally left unlocked. After the finish of infusion treatment, the infusion tube T is blocked by the roller clamp 7 at the moment when the door lock mechanism is unlocked before the opening of the door. This configuration avoids a trouble of removing the infusion tube T from the infusion pump while a user forgets to block the infusion tube by the roller clamp 7.