Laundry dryer (1) comprising an outer casing (2) having a front wall (2a) provided with a laundry loading/unloading pass-through opening, and an air-filtering cartridge (15) which is fitted in removable manner into an air-vent (10) which is passed through by a laundry drying airflow (f), said air-filtering cartridge (15) comprising a first substantially bag- or pocket-shaped, air-filtering shell or vessel (20, 120) which is dimensioned for being inserted/plugged into said air-vent (10) and a second substantially bag- or pocket-shaped, air-filtering shell or vessel (30, 130) which is fitted/recessed into said first air-filtering shell or vessel (20, 120), so as to be passed through by substantially the same airflow (f) that crosses the first air-filtering shell or vessel (20, 120), each of said first and second air-filtering shells or vessels (20, 120, 30, 130) having a two valve-like structure (23a, 23b, 32a, 32b; 123a, 123b, 132a, 132b) which is openable in a book-like manner and has surfaces (21, 121, 31, 131) arranged to restrain fluff and/or lint particles in suspension into the airflow (f). The laundry dryer has the second air-filtering shell or vessel (30, 130) hingedly coupled to the first air-filtering shell or vessel (20, 120), such that, in an open position, both valve-like structures (23a, 23b, 32a, 32b; 123a, 123b, 132a, 132b) displace the inner faces (21a, 21b, 31a, 31b; 121a, 121b, 131a, 131b) of said surfaces (21, 121, 31, 131) on the same side.