In a first aspect a dehumidifying apparatus is suitable for use with storage cabinets having an air inlet 214 and outlet 212, the apparatus comprising (see figures 1-2) housing 110 with air inlet 112 on the side connected to the cabinet outlet 212 via conduit 192 and vent 114 on the top connected to the cabinet inlet 214 via another conduit 194, further comprising compressor 120, evaporator 130, condenser 140, turbo fan 150, fan motor 160 and water collection tank 170 in order to dehumidify air in the cabinet. The apparatus may comprise sterilizing apparatus (figure 1) formed of an ultraviolet light tube 182 and active carbon filter 183. In a second aspect a damp-proof storage cabinet 20 comprises a cabinet body 210 with an air inlet 214 and outlet 212 disposed on a side wall, and a dehumidifying apparatus 10 outside of the cabinet body 210, the dehumidifying apparatus communicating with the cabinet via conduits 192, 194 to dehumidify the air therein. The dehumidifying apparatus may be of a thermoelectric (peltier) type.