The process of sludge digestion using hydrogen peroxide as the only oxidizing agent was carried out. It was pointed out that the application of H₂O₂ to the digestion process is possible provided that aerobic conditions of the process are strictly controlled in the course of process. Since H₂O₂ should be frequently added into digestion chamber it is highly recommended to supply digestion chamber with the aeration system. It was shown that H₂O₂ may also be used to upgrade putrescibled sludge, what is especially important in the break-down events and when the long-term storage is needed.