present invention, in part that narrows the flow path of the infusion tube by the bubble sensor, so as not to leave a portion of the chemical solution, the erroneous detection bubble sensor of the presence or absence of air bubbles to provide an infusion pump that can be prevented from to. The infusion pump (1), the bubble detector (51) is arranged in the open-close cover (5) pressing member (320 as a first member having ultrasonic transmitting unit (321) a) a body (2) is disposed receiving member (330 as a second member having an ultrasonic receiver for receiving ultrasonic waves (331) from the ultrasonic transmitter (321) ) comprises a, in the open-close cover (5) closed, first distance to narrow the flow path of the infusion tube (200) between the first member and the second member compared to (BH1), with respect to the liquid feed direction to send the drug solution (171) of the infusion tube (200), the air-bubble detector of definitive infusion tube also on the downstream side more (51) (200) the second interval narrowing the flow path (BH2), are small rather setting.本発明は、気泡センサにより輸液チューブの流路を狭くしている部分内には、薬液の一部を残さないようにして、気泡センサが気泡の有無の誤検出をすることを防止できる輸液ポンプを提供する。輸液ポンプ(1)では、気泡検出部(51)は、開閉カバー(5)に配置され超音波発信部(321)を有する第1部材としての押し当て部材(320)と、本体(2)に配置され超音波発信部(321)からの超音波を受信する超音波受信部(331)を有する第2部材としての受け部材(330)を備え、開閉カバー(5)を閉じた状態で、第1部材と第2部材との間で輸液チューブ(200)の流路を狭めるための第1間隔(BH1)に比べて、輸液チューブ(200)の薬液(171)を送る送液方向に関して、気泡検出部(51)によりも下流側における輸液チューブ(200)の流路を狭める第2間隔(BH2)が、小さく設定されている。
