A scroll compressor comprising: a partition plate for partitioning an interior of a hermetic container into a high pressure space and a low pressure space; a fixed scroll which is adjacent to the partition plate; an orbiting scroll which is meshed with the fixed scroll and which forms compression chambers; a rotation-restraining member for preventing the orbiting scroll from rotating; and a main bearing for supporting the orbiting scroll, wherein the fixed scroll, the orbiting scroll, the rotation-restraining member and the main bearing are placed in the low pressure space, the fixed scroll and the orbiting scroll are placed between the partition plate and the main bearing, the fixed scroll can move in an axial direction of the fixed scroll between the partition plate and the main bearing, the scroll compressor further includes a first discharge port which is formed in the fixed scroll and which is in communication with the compression chamber, a discharge space which is formed between the partition plate and the fixed scroll, a second discharge port which is formed in the partition plate and which brings the discharge space into communication with the high pressure space a discharge check valve capable of closing the second discharge port, a bypass port which is formed in the fixed scroll and which brings the compression chamber into communication with the discharge space, and the fixed scroll is pressed against the orbiting scroll by a pressure of the discharge space, characterised in that the discharge space is in communication with the first discharge port, and a bypass check valve is capable of closing the bypass port. a partition plate for partitioning an interior of a hermetic container into a high pressure space and a low pressure space; a fixed scroll which is adjacent to the partition plate; an orbiting scroll which is meshed with the fixed scroll and which forms compression chambers; a rotation-restraining member for preventing the orbiting scroll from rotating; and a main bearing for supporting the orbiting scroll, wherein the fixed scroll, the orbiting scroll, the rotation-restraining member and the main bearing are placed in the low pressure space, the fixed scroll and the orbiting scroll are placed between the partition plate and the main bearing, the fixed scroll can move in an axial direction of the fixed scroll between the partition plate and the main bearing, the scroll compressor further includes a first discharge port which is formed in the fixed scroll and which is in communication with the compression chamber, a discharge space which is formed between the partition plate and the fixed scroll, a second discharge port which is formed in the partition plate and which brings the discharge space into communication with the high pressure space a discharge check valve capable of closing the second discharge port, a bypass port which is formed in the fixed scroll and which brings the compression chamber into communication with the discharge space, and the fixed scroll is pressed against the orbiting scroll by a pressure of the discharge space, characterised in that the discharge space is in communication with the first discharge port, and a bypass check valve is capable of closing the bypass port.