A centrifugal blood pump prevents a shaft member from oscillating due to expansion of a pump housing resulting from pressurization of the blood. The centrifugal blood pump is manufactured by assembling a bottom member 21 and a lid member 22, and compressing them in a direction in which the bottom member 21 and the lid member 22 approach each other by a deformation amount along their outer circumferential walls. The lid member and the bottom member are joined while in the compressed state in order to create a preloading force between the shaft member and bearings to resist the expansion due to pressurization of the blood during use.
