To provide a fluid machine, whose reliability and productivity can be improved.

This fluid machine has a seal ring 62 supported by a frame 18 concentrically with the axis of a rotary shaft 16, having an abutment joint 70 formed when opposite circumferential end surfaces 62c and 62d contact each other due to circumferential elongation of the ring which is caused by thermal expansion, and slidingly contacts the back surface 50 of a movable scroll 34 to separate an oil passage 52. The seal ring has a depressurizing means that depressurizes a high-pressure chamber 72 and creates an intermediate-pressure chamber 76 of lower pressure than the high-pressure chamber and of higher pressure than a low-pressure chamber 42, in the oil passage. The depressurizing means is formed in the abutment joint.