Device for the extracorporeal oxygenation of blood of a patient, comprising: a containment casing which has at least an inlet port of the venous blood and at least an outlet port of the arterial blood, at least an inlet channel and at least an outlet channel of a work gas intended to provide oxygen to blood and/or to remove CO 2 from the same; at least a bundle of hollow fibres arranged within said casing and placed between said inlet channel and said outlet channel, said hollow fibres being in communication with said inlet and outlet channels (6, 7) and being intended to be crossed by the work gas; at least a first and at least a second filtering elements (12, 13) arranged inside said bundle of hollow fibres and spaced apart the one from the other, the bundle of hollow fibres having a longitudinal extension, wherein both said filtering elements (12, 13) extend along the entire longitudinal extension of the bundle of hollow fibres and being configured to trap any air bubbles present in the treated blood and characterized by the fact that said first and second filtering elements (12, 13) define, transversally to said longitudinal direction, a relative open profile and that said hollow fibres crosssaid first and second filtering elements (12, 13) uninterruptedly, said first and second filtering elements (12, 13) each having two relative flaps (12a, 13a) which are spaced apart the one from the other, transversally to said longitudinal direction, to define a gap and by the fact that said hollow fibres are arranged inside and outside the open profile defined by the filtering elements themselves and are inserted through said gap. a containment casing which has at least an inlet port of the venous blood and at least an outlet port of the arterial blood, at least an inlet channel and at least an outlet channel of a work gas intended to provide oxygen to blood and/or to remove CO 2 from the same; at least a bundle of hollow fibres arranged within said casing and placed between said inlet channel and said outlet channel, said hollow fibres being in communication with said inlet and outlet channels (6, 7) and being intended to be crossed by the work gas; at least a first and at least a second filtering elements (12, 13) arranged inside said bundle of hollow fibres and spaced apart the one from the other, the bundle of hollow fibres having a longitudinal extension, wherein both said filtering elements (12, 13) extend along the entire longitudinal extension of the bundle of hollow fibres and being configured to trap any air bubbles present in the treated blood and characterized by the fact that said first and second filtering elements (12, 13) define, transversally to said longitudinal direction, a relative open profile and that said hollow fibres crosssaid first and second filtering elements (12, 13) uninterruptedly, said first and second filtering elements (12, 13) each having two relative flaps (12a, 13a) which are spaced apart the one from the other, transversally to said longitudinal direction, to define a gap and by the fact that said hollow fibres are arranged inside and outside the open profile defined by the filtering elements themselves and are inserted through said gap.