The invention relates to a storage cabinet, with at least one of the side walls of said cabinet being arranged in the form of a cassette  (10) containing a deformable curtain (5) , the cassette (10) having two opposite end walls (13) and a slot (15) through which the deformable curtain can be pulled out of the cassette ( 10) or pushed back therein. According to the invention, the cassette includes dedicated cassette stiffener means comprising at least one stiffener strip (21) extending inside the cassette at the slot between the two opposite end walls. Fig. 3
