PROBLEM TO BE SOLVED: To provide a safety needle assembly capable of suppressing an increase in the number of components and the external dimension after the use.SOLUTION: A safety needle assembly 1 includes an outer needle 11, a base body 12, an inner needle 13, and a movable body 14. The proximal end of the outer needle 11 is fixed to the base body 12. The inner needle 13 has a sharp needle tip at a distal end and is inserted into the outer needle 11. The proximal end of the inner needle 13 is fixed to the movable body 14, and the movable body 14 is provided relatively movably from a protrusion position to a storage position. The base body 12 has erecting plates 32 and 32 and a regulating plate 35. When being relatively displaced in the storage position, the erecting plates 32 and 32 regulate the relative displacement of the movable body 14 such that the movable body 14 is not removed from the base body 12. When being relatively displaced to the storage position, the regulating plate 35 regulates the relative displacement of the movable body such that the movable body does not return to the protrusion position.
