The topic of this invention is to provide a compressing and volume reducing apparatus for infectious waste, which can indeed prevent the infectious waste from spreading in implementing the compressing and volume-reducing of medical waste such as infectious waste. The apparatus comprises: a container (2) for containing infectious waste (W) a cover member (3) used to seal the opening part of the container (2) a compressing disk (4) by which a lifting and descending mechanism (5) is used to lift and descend the infectious waste (W) thrown into the container (2) a disinfectant spraying mechanism (6) for spraying the disinfectant fluid inside the container (2) a suction mechanism (7) for sucking the gas in the container (2) and keeping the container (2) in negative pressure a sucked gas sterilization mechanism (8) for sterilizing the gas sucked by the suction mechanism (7) at high temperature a cooling mechanism (9) for cooling the gas that has been sterilized at high temperature by the sucked gas sterilization mechanism (8) and an adsorption deodorization mechanism (10) for adsorbing and deodorizing the stink component of the gas cooled by the cooling mechanism (9).實施醫療廢棄物等感染性廢棄物之壓縮減容化時,可以確實防止感染性物質之飛散之感染性廢棄物的壓縮減容化裝置。用以收容感染性廢棄物(W)之容器(2);用以封閉容器(2)之開口部的蓋構件(3);以昇降機構(5)使被投入容器2內之感染性廢棄物(W)進行昇降之壓縮盤(4);用以對容器(2)內進行消毒液之噴霧的消毒液噴霧機構(6);用以吸引容器(2)內之氣體並使容器(2)內保持負壓之吸引機構(7);用以對吸引機構(7)所吸引之氣體進行高溫殺菌之吸引氣體殺菌機構(8);用以冷卻由吸引氣體殺菌機構(8)進行過高溫殺菌之氣體的冷卻機構(9);以及用以對由冷卻機構(9)冷卻過之氣體所含有之惡臭成份進行吸附除臭之吸附除臭機構(10)。1‧‧‧感染性廢棄物的壓縮減容化裝置2‧‧‧容器3‧‧‧蓋構件4‧‧‧壓縮盤5‧‧‧昇降機構6‧‧‧消毒液噴霧機構(容器內殺菌機構)7‧‧‧吸引機構8‧‧‧吸引氣體殺菌機構9‧‧‧冷卻機構10‧‧‧吸附除臭機構P‧‧‧送出泵T‧‧‧槽W‧‧‧感染性廢棄物