A needleless injection apparatus is provided which forms a suitable contact state between an injection opening from which an injection objective substance is injected and an injection object. The needleless injection apparatus is provided with an expansible bag body arranged so as to surround an outer peripheral surface of the injection object, a needleless syringe including no injection needle, and a gas supply unit for supplying the expansion gas to the bag body. Here, the needleless syringe has a nozzle portion for injecting the injection objective substance toward the injection object surrounded by the bag body, with its injection opening being in a state opposed to the injection object. Then, the bag body includes a first bag portion arranged at any of locations except an arrangement location of the needleless syringe so as to pressurize the injection object by expansion, and a second bag portion arranged at a location at which the nozzle portion is sandwiched between the second bag portion and the injection object so as to push the injection opening to an injection object side by expansion.
