To overcome a problem that the government says a spread period of a fuel cell using hydrogen for achieving energy self-supporting system as fuel will start in 2015, however the expensive manufacturing cost of the fuel cell prove to be a hindrance to widespread use of the system.

In the current home gas co-generation system device which generates electric power by a piston type engine, hydrogen cannot be directly burned. Then, a rotary type engine capable of directly burning hydrogen is produced in this new type inexpensive home gas co-generation system device.