A method is provided for examining the leaktightness of a closed housing of an electrical component. This method includes flooding the housing with a gas mixture that contains a high proportion of an inert gas and a low residual proportion of a gas that can be detected by a measuring probe. During the flooding process, gas that is located inside the housing is forced out of the housing. The method proceeds by determining any leak in the housing by detecting gas escaping from the housing, installing the electrical component when the housing is proven to be leaktight, with the inert gas remaining in the housing.