To improve and use a “buoyancy type power generation method”. A method for harnessing buoyancy and a device therefor are described as prior art in Patent No. JP 5789231 B2 “Buoyancy Type Power Generation Method”. The present invention, adds “self-supply of driving power” as a new feature to the prior art. That is, the present invention is “a self-contained power generation method and a device therefor, for driving itself by means of power produced by itself and for generating power that can be used industrially”. Presented are: a “gap operation type float” and a “rotary type float” which have simple operating methods and configurations as novel power generation devices of the present invention; various devices such as a self-reliant electric-power plant, a bubble injection water maker, a wired electric aircraft, and a seismic isolator as utilization inventions that use the power generation device of the present invention; and various uses of the power generation device of the present i
