PURPOSE: To constitute the uniaxis eccentric screw pump without using an universal joint by pivotally supporting a stator rotatably, directly connecting the rotor to a drive shaft, and concurrently allowing each rotation axis of the stator and the rotor to be one sided.

CONSTITUTION: A rotor 2 is made up of a spiral section 2a having a circular cross section which is off-centered from the rotation axis L1 of the rotor, and of a shaft section 2b in a straight line, so as to be housed in a stator 1. Meanwhile, the stator 1 is pivotally supported rotatably by both a radial bearing 3 and a thrust bearing 4 which are set up in the inside of a pump housing 9. And the shaft section 2b of the rotor 2 is directly connected to a drive shaft 5 across a shaft seal section 6. In this case, the rotation axis L1 of the rotor 2 is made to be off-centered with respect to the rotation axis L2 of the stator 1. This configuration thereby eliminates an universal joint, and it can thereby be achieved that not only a structure is made simple and small in size but also the aforesaid components are made of ceramics.