Abstract: A Stirling engine has an external combustion chamber for burning a kerosene and transferring a high temperature therein to working fluid in heater tubes. In the case of the present invention, the external combustion chamber is connected to a furnace for burning industrial waste materials such as plastic materials or rubber materials so that the high temperature above 900.degree. C. is able to be supplied to the combustion chamber. This serves in raising an output power of the Stirling engine. A conduit for connecting the furnace with the combustion chamber is proveded with a dumper capable of interrupting a flow of the high temperature combustion gases toward the combustion chamber of the Stirling engine.