The invention relates to a method and a system for analyzing rare gases present in a gaseous fluid (1). According to the invention, initially, the rare gases are extracted from the gaseous fluid by trapping by means of a getterizing substrate (5), then superconcentration of the rare gases is produced before injection (8) into the measuring instruments (9). By virtue of the invention, it is possible to increase the partial pressure of the rare gases in the gases to be analyzed before their injection into the analysis instruments.