Provided is a needle-free injecting device which forms a suitable state of contact between an ejection opening, through which a substance to be injected is ejected, and an injection target object. The needle-free injecting device is provided with: an inflatable bag body disposed in such a way as to enclose an outer peripheral surface of the injection target object； a needle-free syringe without an injection needle； and a gas supply device which supplies the bag body with gas for inflation. It is to be noted that the needle-free syringe has a nozzle portion which ejects the substance to be injected toward the injection target object which is enclosed by the bag body, and an ejection opening of the nozzle portion faces the injection target object. Then the bag body has a first bag part which is disposed, in any location except the location in which the needle-free syringe is disposed, in such a way that inflation thereof causes pressure to be applied to the injection target object, and a second bag part which is disposed in a location whereby the nozzle portion is sandwiched between said second bag part and the injection target object, in such a way that inflation of the second bag part causes the ejection opening to be pressed against the injection target object.La présente invention concerne un dispositif d'injection sans aiguille qui forme un état de contact adapté entre une ouverture d'éjection, à travers laquelle une substance à injecter est éjectée, et un objet cible d'injection. Le dispositif d'injection sans aiguille est pourvu de : un corps de sac gonflable, disposé de manière à entourer une surface périphérique externe de l'objet cible d'injection ； une seringue sans aiguille sans aiguille d'injection ； et un dispositif d'alimentation en gaz qui alimente le corps de sac en gaz pour gonflage. Il doit être noté que la seringue sans aiguille comporte une partie de buse qui éjecte la substance à injecter vers l'objet cible d'injection qui est entouré par le corp
