Device for separating out debris suspended in a liquid, for a swimming pool cleaning apparatus, said cleaning apparatus comprising: - a body, - at least one hydraulic circuit circulating liquid between at least one liquid inlet and at least one liquid outlet, and through the device for separating out debris suspended in the liquid, - at least one fluid circulation pump installed in the hydraulic circuit, the device for separating out debris suspended in a liquid including means for the centrifugal spinning of the debris suspended in the liquid, a tank for collecting said centrifugally separated debris, and a liquid supply duct opening into a filtration chamber defining a substantially cylindrical volume, tangentially to a cylindrical wall of said filtration chamber, said filtration chamber communicating with the tank for collecting the centrifugally separated debris, characterised in that the separation device includes, between the filtration chamber and the tank for collecting the centrifugally separated debris, a deflector formed by a portion of a cylindrical wall of the filtration chamber that is extended above the tank collecting the centrifugally separated debris, when the separation device is in position in the body of the cleaning apparatus. - a body, - at least one hydraulic circuit circulating liquid between at least one liquid inlet and at least one liquid outlet, and through the device for separating out debris suspended in the liquid, - at least one fluid circulation pump installed in the hydraulic circuit, the device for separating out debris suspended in a liquid including means for the centrifugal spinning of the debris suspended in the liquid, a tank for collecting said centrifugally separated debris, and a liquid supply duct opening into a filtration chamber defining a substantially cylindrical volume, tangentially to a cylindrical wall of said filtration chamber, said filtration chamber communicating with the tank for collecting the centrifugally separated debris, characterised in that the separation device includes, between the filtration chamber and the tank for collecting the centrifugally separated debris, a deflector formed by a portion of a cylindrical wall of the filtration chamber that is extended above the tank collecting the centrifugally separated debris, when the separation device is in position in the body of the cleaning apparatus. the device for separating out debris suspended in a liquid including means for the centrifugal spinning of the debris suspended in the liquid, a tank for collecting said centrifugally separated debris, and a liquid supply duct opening into a filtration chamber defining a substantially cylindrical volume, tangentially to a cylindrical wall of said filtration chamber, said filtration chamber communicating with the tank for collecting the centrifugally separated debris, characterised in that the separation device includes, between the filtration chamber and the tank for collecting the centrifugally separated debris, a deflector formed by a portion of a cylindrical wall of the filtration chamber that is extended above the tank collecting the centrifugally separated debris, when the separation device is in position in the body of the cleaning apparatus.