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). FIG. 1.