PROBLEM TO BE SOLVED: To avoid action of a combustion product generated by explosive combustion on an injection objective substance, and to suitably transmit energy for an injection to the injection objective substance, in an injection syringe.SOLUTION: An injection syringe comprises an injection body, a syringe part, a first piston part, an ignition device, and a sealing member. The first piston part includes a prescribed end surface for receiving injection energy. The sealing member seals a combustion product to be generated by the ignition device within a first space on the side of the ignition device sectioned by the sealing member, and further includes a fixing end part and a contact part making contact with the prescribed end surface. In a state before explosive combustion by the ignition device, the contact part is positioned in a starting position on the side of the ignition device with respect to the fixing end part. By the explosive combustion by the ignition device, the contact part makes contact with the prescribed end surface and moves to an injection position on the side of the syringe part with respect to the fixing end part together with the sliding of the first piston part.SELECTED DRAWING: Figure 4
