The present invention relates to a steam sterilization apparatus, and more particularly, to a steam sterilization appa-ratus in which a crack in a vaporization space is minimized to achieve maximized water vaporization efficiency and to reduce the size of the apparatus, and which prevents liquid phase water from being sprayed at an early stage of operation of the apparatus to achieve a steam sterilization effect from the early stage of operation of the apparatus. The steam sterilization apparatus according to the present invention comprises: a case which forms a main body a water container arranged in an inner rear portion of the case to store water a liquid chemical container arranged behind the water container to store a liquid chemical a nozzle assembly which is arranged in an inner front portion of the case and which includes a steam nozzle for receiving water from the water container and spraying water to the outside, and a liquid chemical nozzle for receiving a liquid chemical from the liquid chemical container and discharging the liquid chemical to the outside a water supply pipe which interconnects the water container and the steam noz¬zle a liquid chemical supply pipe which interconnects the liquid chemical container and the liquid chemical nozzle a healer block interposed between the water supply pipe and the steam nozzle to heat and vaporize the water supplied through the water supply pipe a pump installed at the water supply pipe to apply pressure to the water in the water container and to supply water through the water supply pipe and a control unit which controls the operation of the pump and of the heater block.
