A gas sterilization apparatus comprises a housing with a sterilizing unit and a power device. An ozone generator and an air purifying device are provided in the housing. The power device is operated to allow air to pass through the ozone generator and flow into the sterilizing unit so as to perform sterilization. After being sterilized, the air in the sterilizing unit can be drained via the purification of the air purifying device. The gas sterilization apparatus can sterilize the air by use of ozone, thus it is applicable for articles and materials which can be sufficiently soaked by ozone to achieve the sterilization effect, and it can reduce the denaturation of biological materials, so it has wide application. The gas sterilization apparatus can sterilize the articles and materials in simple and convenient ways for user, so it is beneficial to use in the industry.
