An apparatus for sterilizing post-consumer absorbent sanitary products, comprising: - a container (12) rotatable about a longitudinal axis (A), having a closed first end (16) and a second end (18) provided with an opening (22) for loading/unloading, closed by a removable door (24), wherein the container (12) has a hollow wall (26) including an inner wall (28), an outer wall (30), and a hollow space (32), which extends from said first end (16) to said second end (18), - a rotary joint (34) located at said first end (16) of the container (12) and having a steam inlet chamber (48) and a condensate discharge chamber (50), - at least one hollow helical blade (70), which extends between said first end (16) and said second end (18) of the container (12) and protrudes inwardly from said inner wall (28) of the container (12), wherein said hollow helical blade (70) has a helical cavity (72) having an inlet (78) in fluid communication with said steam inlet chamber (48) at said first end of the container (16), an outlet (80) in fluid communication with said hollow space (32) at said second end (18) of the container (12), and is closed between said inlet (78) and said outlet (80), wherein the condensate discharge chamber (50) of said rotary joint (34) is in fluid communication with said hollow space (32) in said first end (16) of the container (12), so that the steam coming from said steam inlet chamber (48) flows into said helical cavity (72) from said first end (16) towards said second end (18) and, subsequently, flows into said hollow space (32) from said second end (18) toward said first end (16).
