Abstract: A method of filling a sealed elastomer chamber (2, 6, 8) with gas is provided, wherein the chamber is filled with the gas chemically produced by thermal decomposition of a gas producing material (12, 14, 16) inside of the chamber itself using a usual means of a high frequency electromagnetic heating. This method is easier than a conventional gas filling method by charging a compressed gas from outside of the chamber to obtain a desired internal pressure in the chamber, and makes it possible to fill more than two sealed elastomer chambers individually with gas at one time.