Abstract: A one-way degassing valve (4) for containers of aromatic products such as coffee and the like, comprising a valve body (5, 6), a valve element (12) and a filter (17), comprising a selective filter layer (21a), preferably consisting of activated charcoal, which allows the passage of low molecular weight gases, such as carbon dioxide, and retains high molecular weight gases that constitute the product's aroma, and an oxygen and CO2 adsorbing layer (21b), able to eliminate the residual oxygen present in the container and suitably reduce the amount of CO2.