PURPOSE: To reduce the dimension of an engine per output by forming one among a pair of engine constitution bodies as one of the high and low temperature working chambers which constitutes a Stirling cycle and forming the other working chamber as the other of the high and low temperature working chambers.

CONSTITUTION: As for each engine body constitution body 1, 1', working chambers A-D and A'-D' are formed from a plurality of trochoid shaped rotors 2 and 2' and a housing 3 having rotor accommodation chambers 7 and 7' each of which is formed from the outer envelope of the rotor, and in each engine constitution body 1, 1', a plurality of working chambers are formed, and fixed on a housing side, and a plurality of working chambers are utilized as a high or low temperature working chamber which forms the Stirling cycle in each engine constitution body, and a pair of engine constitution bodies can constitute a plurality of Stirling engines. Accordingly, in comparison with a reciprocation movement type, the number of working chambers per rotor can be increased, and the dimension of the engine per output can be reduced.