The invention relates to a swimming pool cleaning apparatus comprising: at least one hydraulic liquid circulation circuit between at least one liquid inlet (3) and at least one liquid outlet (4), and through a removable filtration device of the cleaning apparatus. The filtration device comprises at least one filtration chamber (8) comprising: a cover (2), a filtration basket (17), the hydraulic fluid circulation circuit comprising a liquid discharge tube (20) emerging from the apparatus through an opening (4) formed in the cover (2) of the filtration device, the filtration basket (17) comprising a central filtering wall (9) surrounding the liquid discharge tube (20) over at least a part of its length.