PURPOSE: To reduce the axial thrust and to increase the load capacity of a compressor by forming most part of a spiral of a conveying space and compression body with a first curvature, and forming an exit-sided end with a second small curvature over a specific angular range.

CONSTITUTION: The rotor of a spiral compressor comprises two spirally expanded compression bodies (projection) 3a, 3b shifted from each other by 180° on an end surface of a disc, and the compression bodies 3a, 3b are respectively inserted between the cylinder walls 14a, 14b, 15a, 15b provided surroundingly on the spiral which spans a circumferential angle of 360°. The fluid taken in the conveying spaces 11a, 11b from the inlets 12a, 12b by the eccentric rotation of the compression bodies 3a, 3b is successively compressed and discharged from an outlet 13. On this occasion, most part of the spiral of the conveying spaces 11a, 11b and the compression bodies 3a, 3b is formed with a first curvature, and an exist-sided end is formed with a second small curvature over an angular range of approximately 30°-90°.