Disclosed herein is an apparatus for storing hazardous material. The apparatus includes storage containers each of which stores a hazardous material storage box containing hazardous material. The hazardous material storage box is extracted from or retracted into the storage container by a transfer means. A fire sensor is provided in each storage container to detect a fire occurring in the storage container. A temperature sensor is provided in each storage container to sense a temperature in the storage container. An injection nozzle is provided in each storage container. The injection nozzle injects nitrogen into the storage container from a nitrogen supply unit when a fire is detected. An outlet pipe connection passage and a flexible outlet pipe connection tube are provided to exhaust gas from the storage containers. A collecting container is provided in the lower end of the apparatus to collect and store leakage liquid of hazardous material.