The present invention is directed to a safety needle assembly (100) having the high safety and high operability, comprising: a hub (1)； a cannula (2)； a collar (3)； a protector (4)； and a sheath (5). The sheath (5) includes an opening of housing the cannula (2)； a cannula fixing part of locking the cannula (2) housed in the opening； an attachment part of rotatably supporting the sheath (5) attached to the hub (1) or the collar (3)； and a protrusive stopper which a user pushes by a finger to pivot the sheath (5) thereby to house the cannula (2) in the opening of the sheath (5). Herein, the stopper is arranged at a vicinity of a central portion of the sheath (5) in a longitudinal direction at the opposite side of the aperture of the opening, or arranged at a portion closer to a distal end side than the central portion of the sheath (5).
