The invention relates to a method and a device for the purification of air by passing a flow of the air through a filter having a photocatalytic action subjected to UV lighting, said filter comprising a felt of mineral fibers, the fibers of which are coated with a material having a photocatalytic action, the residence time of the air in contact with the filter being greater than 70 msec and the UV lighting having a power of less than 35 mW per cm2 of lit surface of filter having a photocatalytic action. The invention is particularly effective in removing volatile organic compounds from the air.