The present invention is made to securely position a needle tip and a blade face of a needle tube inserted into the skin in a predetermined site of a living body, such as the upper layer of skin. An injection needle assembly includes a needle tube (2) having a needle tip capable of puncturing a living body, a hub (3) holding the needle tube, a stabilizer (4), and a guide portion (7). The stabilizer (4) is formed in a tubular shape surrounding the circumference of the needle tube (2), and an end face (6b) is pressed against the skin, and thereby a raised portion of the skin is formed in a tube hole (6a). The guide portion (7) is arranged on the stabilizer (4), and is adapted to recognize a press-in distance of the stabilizer (4) to the skin.
