PURPOSE: To provide a small case diameter for a given compressed volume by securing a scroll body on a disc permitting the outermost of scroll body and the edge of a disc to coincide with the center of the disc to shift from the center of the scroll to the outermost.

CONSTITUTION: A disc 241 diameter of displaceable scroll section 24 indicates (2a-R), a showing the distance from the center of a scroll body 252 to the outermost thereof, and R showing the eccentric dimension of a crank pin 24, then, the center thereof being shifted from the center of the scroll body 242 to the outermost thereof to coincide the outermost thereof with the peripheral edge of the disc 251. Additionally, the center of the housing 10 is shifted from the center of the scroll 252 with R/2 with the opposite direction of the outermost of the scroll body. This permits the diameter of housing 10 to make small with providing a small compressor.