ABSTRACTas possible to nazi an , •obaective—substance to a. depth or a skin structure of an objective -j-.-) body without asiog any inlection needle. A syringe having no injection needle comprises &E. enclosing unit which encloses the injection. objective substance, Ci pressullliihg unit which pressurizes the injection objective substanke enklubsd in the enclosing unit, and a flow passage unit which defines a flow passage so that the injection objective sulzstance, which is pressurized he toe pressurizing unit, is allowed to inject to an injection target area. The pressurizing unit has a firstpressurizing mode in which a pressure applied to the injection objective substance in the pressurizing unit s ralbod to a I:list peak ptesogre in. nrhPr to form a benetratinj passage in the injection target area, and then the pressure applied to the injection ohtecjive substance is lowered to a. waiting Pressure, ante second pressurizing mode in which the injection objective substance having the waitinj pressure is pressurized so that the pressure apyjied to the injection objective substance is raised. to a SCCOnd peak pressure to inject a htedetedmined injection amount of the injection objective substance.
