A needleless injector is provided. The needleless injector includes a loading lever having a working arm part having a lever shaft, a towing member inserted inside the cylinder housing, a link having one end portion pin-coupled to the working arm part and the other end portion pin-coupled to the towing member, an inner cylinder inserted inside the cylinder housing, a spring inserted into the inner cylinder, an actuating head inserted into the inner cylinder in front of the spring and having a catching protrusion configured to be inserted into the slit, and a trigger means having a stopper head part configured to be able to be inserted into the slit of the inner cylinder and detached from the slit. Accordingly, the needleless injector can achieve a reduction in size and thickness by having a simple structure even with a lever for reloading integrally formed therein.
