To provide a medical needle capable of moving to projection moving end which can prevent the automatic return of released cover member and limiting the return movement of the projection positioned at said projection moving end. The cover member (6) is such formed that projection (6a) is guided by a guide portion (4e) and led to projection moving end (4h), from a received pose in which the projection (6a) is secured in securing portion (4f) in the biased state by means of spring (7) and received in retaining body portion (4c), to a covered pose in which said secured state is released and needle exposure portion (2a) is covered. A return preventing portion (4j) is formed from and in connection with projection moving end (4h) toward base direction. Furthermore, a movement limiting portion (4m) is provided which is nearer to base side than return preventing portion (4h), nearer to front side than return movement end (4w) of return preventing portion (4j), and formed in retaining body portion (4c) in the manner of departing from base side in the state that it is opposite to the projection (6a) positioning at projection moving end (4h) with a gap (S) existing therebetween, within the range of gap (S), the return movement limiting portion (4m) is brought in to contact with the projection (6g) raised from projection moving end (4h).本發明提供一種可移動至可防止已解除卡止之包覆構件自動返回的突起部移動端,且可限制位於該突起部移動端的突起部之返回移動的注射器。本發明之醫療用針中,包覆構件(6)係從在受到彈簧(7)彈壓的狀態下,將突起部(6a)卡止在卡止部(4f)而收容在保持部主體部(4c)的收容姿勢,由引導部(4e)引導成使前述卡止狀態解除而成包覆針管露出部(2a)的包覆狀態,並以誘導至突起部移動端(4h)的方式形成,從突起部移動端(4h)朝向基端方向連結形成有防止返回部(4j),又,以比突起部移動端(4h)更靠近基端側、比防止返回導件(4j)的返回移動端(4w)更靠近前端側,相對於位在突起部移動端(4h)的突起部(6a)保持空隙(S)而相對向的狀態,與基端側分開而形成於保持部主體部(4c),並且設有抵接於在間隔(S)的範圍內從突起部移動端(4h)升起的突起部(6a)的返回移動限制部(4m)。4e...引導部4i...第二導件4j...防止返回導件4l...第一導件4m...返回移動限制部4n...移動限制部前端4p...連續部位6a...突起部6b...開縫
