An injection needle assembly includes a needle tube 2 having a needle tip capable of being stuck into a living body, a hub 3 holding the needle tube 2, a stabilization unit 6 arranged so as to cover the circumference of the needle tube 2 in a condition that the needle tip of the needle tube 2 protrudes and having an end face 6c that contacts the skin when causing the needle tube 2 to be stuck into the living body, and housing units 7 and 8. The housing units 7 and 8 are movable along the axial direction of the needle tube 2 from the first position where the needle tip of the needle tube 2 is exposed to the second position where the needle tip of the needle tube 2 is housed.