An apparatus for treating used absorbent sanitary products, comprising: - a rotary cylindrical autoclave (14) having an inner surface (22) and two ends, at least one of which terminates in a hatch (18, 20) that can be opened to enable access to said autoclave (14) and sealably closed to enable pressurization of said autoclave (14) and - a circuit for heating and pressurizing the autoclave (14) for heating the absorbent sanitary products to a sterilization temperature, wherein said autoclave (14) comprises a sealing layer (48) on said inner surface (22), designed to prevent adhesion on said inner surface (22) of material coming from destructuring of said absorbent sanitary products.