The present invention relates to a laundry dryer. A laundry dryer (1) according to the invention comprises a laundry treating chamber (3), a drying air circulating conduit (12) extending through the laundry treating chamber having a drying air outlet section (36) for exhausting drying air from the chamber (3), wherein the laundry dryer further comprises a drying air-filtering cartridge (5,52,53,54,55) which is fitted in a removable manner into a seat (6) formed in the air outlet section, the drying air-filtering cartridge comprising: two shells (23a,23b) associated one another, a first air permeable surface (21) extending from one shell towards the other shell for allowing drying air entering the air-filtering cartridge, and a second air permeable surface (22) for allowing exhausting drying air from the air-filtering cartridge, the first and the second surfaces being connected through lateral side walls (24a-d). A laundry dryer according to the invention is characterized in that at least one drying air inlet pass-through opening (9a-d,93a,b,94e,f) is formed in a portion of said lateral walls resting within the seat when the air-filtering cartridge is fitted thereinto.