An indwelling needle assembly and protector. The indwelling needle assembly has an inner needle, an inner needle hub, an outer needle, an outer needle hub, and a protector for protecting the needle point of the inner needle arranged on the outer periphery of the inner needle so as to be slidable in the axial direction. The protector includes a protecting member in which the needle point of the inner needle is stored and a closing member arranged on the outer periphery of the protecting member so as to be capable of sliding, a displaceable side wall which is capable of being displaced inward so as to close a distal opening of the protecting member, the displaceable side wall being displaced inwardly by the closing member arranged on the outer periphery of the distal end portion of the protecting member.
