The present invention relates to a portable sterilized water spray gun using air pressure and, more particularly, comprises: a power supply main body having a controller provided at the upper side thereof, and having a handle having a spray nozzle and an operating lever so as to spray sterilized water; a storage container storing the sterilized water sprayed through the power supply main body, and provided so as to be separable and coupleable at the lower side of the power supply main body; a sterilized water supply unit fixedly provided at the lower side of the power supply main body so as to supply the sterilized water, which is stored in the storage container, to the power supply main body by the air pressure; and a sterilized water producing unit fixedly provided at the lower side of the sterilized water supply unit so as to electrolyze raw water inside the storage container, thereby producing the sterilized water.
