To provide a double scroll type fluid machine compact and lightweight with high performance and capable of having large capacity.

In this double scroll type fluid machine, a compression or expansion mechanism is composed of a fixed scroll formed with a first scroll body in a easing, and a turnable movable scroll built in eccentrically to the fixed scroll and formed with a second scroll body on an end plate so as to be engaged with the first scroll body, and another compression or expansion mechanism is symmetrically arranged. Both movable scrolls are arranged on both sides of a housing. A main shaft is rotatably supported in the housing, and a plurality of crankshafts are rotatably disposed on the concentric circle of the main shaft. Both end parts of each crankshaft are provided with crankpins eccentric by a specified quantity, and the main shaft and each crankshaft are connected in a rotational force transmittable manner through a timing gear. The crankpins at both end parts of each crankshaft are fitted to bearings provided at the opposed faces of the end plates of both movable scrolls, and both movable scrolls are put in turning motion through the rotation and turning motion of the respective crankpins.