The present invention relates to a portable oral cavity cleansing apparatus, and more particularly, to the portable oral cavity conveniently used due to selective spray of cleansing water contained inside of a cleansing solution container as needed through a nozzle tip and having small numbers of parts due to a remarkably simple structure for spraying the cleansing solution as well as having excellent productivity and marketability when manufactured. The portable oral cavity cleansing apparatus of the present invention (1000) comprises: the cleansing solution container (1100) in cylindrical shape provided with a containing portion by having one end open； a compression spring (1200) elastically inserted in the containing portion； a piston (1300) fixed on the compression spring from the open side of the container so as to tightly contact in a direction of the inside and the circumference of the container, such that the cleansing solution filled in the container can be discharged to the open side； a cleansing solution spray adjusting cap (1400) coupled with the open side of the container so as to prevent the piston from being deviated from th container； a valve shaft (1600) inserted in a shaft direction in a flow path formed inside of the cleansing solution spray adjusting cap and capable of elastically moving in the opposite direction of the piston by a valve spring (1500)； a valve sheet (1700) inserted into the valve shaft projected toward the piston so as to selectively block the flow path； an operating button (1800) inserted into a shaft direction from the outer circumference surface of the cleansing solution spray adjusting cap so as to move the valve shaft toward the piston by opposing the elastic and repellent force of the valve spring, and thereby, opening the flow path； and the nozzle tip (1001) detachably assembled on the other end of the cleansing solution spray adjusting cap so as to spray the cleansing solution.본 발명은 휴대용 구강세정기에 관한 것으로, 특히 세정액수용용기의 내부에 수용된
