Potato treatment wastes (peel waste, shredded potatoes, fry waste, potato pulp, brine potatoes, gray starch, potato juice) were fermented at 38 degrees C and pH 6:5-7.5 under anaerobic condition to MeH-rich biogas. After 10-15 days, the biogas yield was 400-650 Nm(3)/t of dry mass. The biogas contained 52-72% of MeH.