Abstract: Method for fumigating products (2) in an enclosed space (4), which consists in making the air in this space (4) circulate in a closed circuit through at least one flow-through module (13, 38-42) with adsorption material (15) in which treatment gas has been adsorbed; in activating means (16) which release the treatment gas from the adsorption material (15) until a sufficient quantity of treatment gas has been blown in the enclosed space (4); in switching off the means (16); and, as soon as the products (2) have been sufficiently fumigated, in recycling the treatment gas again by making the mixture of air/treatment gas circulate via the flow-through modules (13, 38-42) in order to have the treatment gas adsorbed in the adsorption material (15).