Abstract: For a deep fat fryer comprising a vat containing a bath of heated oil, there is provided a built-in device for filtering the oil, including means for collecting the oil contained in the vat, and means for pumping, for filtering and for recirculating this oil to the vat. The filtering device comprises, on the one hand, a filtering unit situated in the upper part of the vat of the deep fat fryer, in a readily accessible location, at the downstream end of the recirculating means and, on the other hand, arranged inside the cabinet of the deep fat fryer, a motor and a pump, particularly a rotary pump, driven by the motor. The invention applies to industrial or commercial deep fat fryers.