PURPOSE: To stably give sealing performance with reliability without increase in input by keeping a space surrounded with a main frame and a bearing plate at suction pressure, and using slide bearings between a rotating shaft and the main frame, and between a driven scroll and an eccentric bush.

CONSTITUTION: The lower setting range of an engagement part of a rotating shaft 8 of a driving scroll 4 and a main frame 11 and the upper setting range of an engagement part of a driven scroll 5 and an eccentric bush 16 respectively function as a shaft seal of slide bearings 32, 33. A high pressure part 13 and a low pressure part 12 are partitioned by the sealing performance of the slide bearings 32, 33 through the above seals to hold a pressure difference, so that stable rotation can be obtained. The space between the lower surface 5a of a end plate of the driven scroll 5 and the central upper end part 15a of a bearing plate 1 5 is near the shaft seal so that a proper quantity of oil flows into the low pressure part 12. Accordingly, there is no friction of the seal member so that the power consumption can be reduced and stable sealing performance can be obtained.