In a double rotation type scroll expander having double expansion chambers, a single integrated drive shaft is disposed to penetrate the interior of a housing, the double expansion chambers are formed by a drive scroll body and a driven scroll body, and a working medium introduction hole is provided in an axial direction of the drive shaft such that the working medium is supplied evenly to the double expansion chambers through the working medium introduction hole via a radial direction hole. The drive shaft and the drive scroll body formed integrally with the drive shaft rotate while the driven scroll body rotates synchronously with the drive scroll shaft via an interlocking mechanism.