A disposable cassette intended for a metering pump for infusion consisting of just two components, namely, a hollow first component (1) forming a pump body, and a second component (5) collaborating with the hollow first component (1) to form a pumping zone (6) and comprising a flexible part (10) characterized in that the second component (5) further comprises a rigid part (9) secured to the flexible part (10) and able to be assembled with the hollow first component (1). The invention also relates to a method for manufacturing such a disposable cassette.