Centrifugal-separation oil separation means which comprises: an outer cylinder that extends in an axial direction; an inner cylinder that passes through the interior of the outer cylinder in the axial direction; a pair of end plates (4a, 4b) provided at both ends of the outer cylinder; an inlet port that is connected to the outer cylinder near one of the end plates and that introduces an oil-containing fluid discharged from a compressor into a space formed between the outer cylinder and the inner cylinder so as to swirl about the axis; an outlet port that is connected to the outer cylinder near the other end plate and that expels the fluid, from which the oil has been centrifugally separated, out of the space; and an oil discharge port, provided in the outer cylinder, for discharging the separated oil out of the space, wherein a partition plate (8, 9) that extends over at least part of a cross-section perpendicular to the axial direction to partition the space in the axial direction is provided in the space, characterized in that the partition plate (8, 9) comprises a first partition plate which is provided in an area from a connecting end of the inlet port connected to the outer cylinder to a position of more than 30° and less than 135° in the circumferential direction of the swirling fluid, and a second partition plate which is provided in the form of a ring in the space, near the inlet port, between the one end plate and the inlet port. an outer cylinder that extends in an axial direction; an inner cylinder that passes through the interior of the outer cylinder in the axial direction; a pair of end plates (4a, 4b) provided at both ends of the outer cylinder; an inlet port that is connected to the outer cylinder near one of the end plates and that introduces an oil-containing fluid discharged from a compressor into a space formed between the outer cylinder and the inner cylinder so as to swirl about the axis; an outlet port that is connected to the outer cylinder near the other end plate and that expels the fluid, from which the oil has been centrifugally separated, out of the space; and an oil discharge port, provided in the outer cylinder, for discharging the separated oil out of the space, wherein a partition plate (8, 9) that extends over at least part of a cross-section perpendicular to the axial direction to partition the space in the axial direction is provided in the space, characterized in that the partition plate (8, 9) comprises a first partition plate which is provided in an area from a connecting end of the inlet port connected to the outer cylinder to a position of more than 30° and less than 135° in the circumferential direction of the swirling fluid, and a second partition plate which is provided in the form of a ring in the space, near the inlet port, between the one end plate and the inlet port. a first partition plate which is provided in an area from a connecting end of the inlet port connected to the outer cylinder to a position of more than 30° and less than 135° in the circumferential direction of the swirling fluid, and a second partition plate which is provided in the form of a ring in the space, near the inlet port, between the one end plate and the inlet port.