Abstract: This invention corresponds to a device that delivers sulfur dioxide (SO2) in a controlled manner after getting in touch the active ingredient of the device, sodium metabisulfite, with humidity. The most important characteristic of the invention is that emission control of the gas is obtained with one or several homogeneous layers of the active ingredient at different concentrations allowing, if required, for a multilayer generator system with fast and slow emission of SO2 making use additionally of physical barriers specially designed for controlling the flux of water and SO2 through them. The invention also discloses the methods of obtaining the SO2 generator device.