PROBLEM TO BE SOLVED: To reduce a load on a nozzle or to reduce noise in time of injection without reducing convenience of a user, in a needleless syringe.SOLUTION: This needleless syringe for injecting an injection target substance into an injection target region of a living body without interposition of an injection needle includes: a syringe body a storage part storing the injection target substance in a storage chamber formed in the syringe body through a sealing member a pressurization part moving or destroying the sealing member by pressurizing the injection target substance which is stored in the storage part to discharge the injection target substance to the outside a flow path part formed with an ejection port to the injection target region, and delimiting a flow path such that the injection target substance pressurized by the pressurization part is ejected to the injection target region through the ejection port and an advance filling part destroying a part of the sealing member before the pressurization by the pressurization part is performed to fill the injection target substance inside the storage chamber in the flow path part.COPYRIGHT: (C)2012,JPO&INPIT【課題】無針注射器においてユーザの利便性を低下させることなく、注射時におけるノズルに対する負荷軽減や騒音の低減を可能とする。【解決手段】注射針を介することなく、注射目的物質を生体の注射対象領域に注射する無針注射器であって、注射器本体と、注射器本体に設けられた収容室内に、封止部材を介して注射目的物質を収容する収容部と、収容部に収容された注射目的物質に対して加圧することで封止部材を移動又は破壊させて、該注射目的物質を外部へ排出させる加圧部と、注射対象領域への射出口を形成し、加圧部によって加圧された注射目的物質が注射対象領域に対して該射出口を介して射出されるように流路を画定する流路部と、加圧部による加圧が行われる前に、封止部材の一部を破壊して、収容室内の注射目的物質の一部を流路部に充填させる事前充填部と、を備える。【選択図】図1
