To provide a rotary fluid machine which has a simple constitution and consists of a small number of components, and can be produced at a low cost.

A rotary fluid machine has its structure simplified by: housing a fluid transfer rotor 362 in a rotor operation chamber 360 in a rotatable manner; supporting first and second movable closures 368 and 368A by a housing 352 so that the movable closures cross a first outlet 358 and a second outlet 358A; bringing curved-surface seal parts 376a of the first and second movable closures into slide contact with slide recessed parts 366A, 366B, and 366C of the fluid transfer rotor in a fluid-tight manner while a first inlet 356 and the outlet 358, and a second inlet 356A and the outlet 358A are made not to communicate with each other; and forcibly discharging the fluid from the first outlet and the second outlet through an opening part 376b formed on a rear side of the curved surface seal part.