[Object]To provide an infusion tube misfitting detection means for an infusion pump, which can be implemented at a low cost with a safety maintained.[Solving Means]When a door unit 20 is to be closed with respect to a pump body 10 in a misloaded state of an infusion tube 40, a misload detection inner door 25 is pressed by the infusion tube 40 to operate on a handle lock part 23A provided to a handle 23. Accordingly, a claw portion 23Ac of the handle lock part 23A is pushed up, so that the door unit 20 cannot be locked with the pump body 10 by inserting the claw portion 23Ac into a rectangular through-hole 11c of a base plate 11. Therefore, the misloaded state can be identified.