PROBLEM TO BE SOLVED: To provide an infusion pump capable of preventing an air bubble sensor from erroneously detecting the presence or absence of air bubbles by preventing a part of a liquid chemical from remaining in a portion where a flow channel of an infusion tube is narrowed by the air bubble sensor.SOLUTION: In an infusion pump 1, an air bubble detection part 51 comprises a press contact member 320 as a first member disposed in an opening/closing cover 5 and having an ultrasonic transmission part 321, and a reception member 330 as a second member disposed in a body part 2 and having an ultrasonic reception part 31 for receiving an ultrasonic wave from the ultrasonic transmission part 321. In a state of closing the opening/closing cover 5, as compared with a first interval BH1 for narrowing a flow channel of an infusion tube 200 between the first member and the second member, a second interval BH2 for narrowing the flow channel of the infusion tube 200 on the downstream side from the air bubble detection part 51 is set smaller in a liquid feeding direction in which the infusion tube 200 feeds a liquid chemical 171.SELECTED DRAWING: Figure 8
