PROBLEM TO BE SOLVED: To provide a needleless syringe with which a relatively shallow part of injection regions of a living body or the like is injected and which has a structure as simple as possible.SOLUTION: The needleless syringe comprises: a filling part which is filled with a substance to be injected a pressurization part for applying pressure to the substance to be injected which is filled in the filling part an ejection part haning a passage through which the substance to be injected flows which is pressurized by the pressurization part and which ejects the substance to be injected from an open end of the passage to an injection region on the outside of the syringe, the open end having an area smaller than the area of the passage in the filling part and a micropore part which has micropores with a smaller area than the area of the open end of the ejection part and is disposed at the outside of the open end so that the substance to be injected that is ejected from the open end may reach the injection region side via the micropores.COPYRIGHT: (C)2013,JPO&INPIT【課題】生体等の注射対象領域の比較的浅い部位に対して注射可能であって、可及的に簡素化された構造を有する無針注射器を提供する。【解決手段】注射針の無い注射器であって、注射目的物質を封入する封入部と、封入部に封入された注射目的物質に対して加圧する加圧部と、加圧部によって加圧された注射目的物質が流れる流路を有し、該注射目的物質が該流路の開口端から注射器の外部の注射対象領域に対して射出される射出部であって、該開口端は、その面積が封入部の流路面積より小さくなるように形成されている射出部と、射出部の開口端の面積より小さい流路面積を有する微小細孔を含み、該開口端から射出される注射目的物質が該微小細孔を通過して注射対象領域側へ到達するように、該開口端の外側に配置される微小細孔部と、を備える。【選択図】図1
