It is possible to feed an injection objective substance to a depth of a skin structure of an objective living body without using any injection needle. A syringe having no injection needle comprises an ignition device which includes an ignition charge containing a fuel component and an oxidizing agent component, a combustion chamber into which a combustion product produced by a reaction of the fuel component and the oxidizing agent component during combustion of the ignition charge is allowed to flow and which accommodates a gas generating agent that is combustible by the combustion product to generate a predetermined gas, and an enclosing unit which encloses the injection objective substance, wherein the injection objective substance enclosed in the enclosing unit is pressurized by a pressure in the combustion chamber in this construction. The fuel component and the oxidizing agent component contained in the ignition charge are determined so that any component, which behaves as a gas, is excluded from the combustion product when the combustion product is at ordinary temperature in the case where the fuel component and the oxidizing agent component are mixed at a stoichiometric ratio and combusted, and a cooling member is arranged in the combustion chamber so that the cooling member can be brought in contact with the combustion product produced by the combustion of the ignition charge to cool the combustion product.
