The purpose of the present invention is to provide an injection needle assembly making it possible to selectively inject a drug solution to the upper layer of the skin, and in particular, to a relatively shallow site in the dermal layer, closer to the epidermal layer, irrespective of age differences, gender differences, individual differences, or treatment history, without leakage from the skin surface, so as to form a wheal and acquire an ability to induce immunity and the like even with a very small amount. An injection needle assembly (10) comprises: an injection needle (20) composed of a needle tube which is provided with a needle hole (24) communicating from a needle tip (21) to a needle base end (23) and which has an edge face (22) at the needle tip (21)； and a needle hub (30) that has a tip end section (31c) and base end section, and retains the injection needle (20) at the tip end section (31c). The needle hub (30) has a needle tip-side end surface (31b), from which the needle tip (21) protrudes out. The injection needle (20) is configured such that an outer diameter (φ1) is 0.15 to less than 0.20 mm, a protruding needle length (L1) from the needle tip-side end surface (31b) to the needle tip (21) is 0.50 to 1.25 mm, and a needle body length (L2) from the needle tip-side end surface (31b) to the edge face (22) is 0.10 to 0.70 mm inclusive.L'objet de la présente invention est de fournir un ensemble aiguille à injection permettant d'injecter sélectivement une solution médicamenteuse dans la couche supérieure de la peau, et en particulier, un site relativement peu profond dans la couche dermique, plus proche de la couche épidermique, indépendamment des différences d'âge, des différences de sexe, des différences individuelles, ou des traitements suivis, sans fuite de la surface de la peau, de manière à former une papule œdémateuse et à acquérir une capacité à induire une immunité et similaire, même avec une très faible quantité. Un ensemble (10) aiguille à injec
