PURPOSE: To prevent leakage of fluid thus to improve the performance of machine by providing a member for limiting the relative torsional position of scroll members directly between scroll members thereby setting the torsional position of scroll member accurately.

CONSTITUTION: Fixed scroll member 600 is secured to the housing 10 while a movable scroll member 601 is pivoted by pin 611 to the fixing metal 610 of housing 10 through an arm 607, a pin 608 and a link 609. Consequently, the circumferential position of fixed scroll member and housing, fixed metal and housing can be set accurately. The relative torsional adjusting is performed through motion of housing.