A protector mounted on a needle body including an elongate main needle body, the protector being shiftable from a first posture capable of relatively moving along a longitudinal direction of the needle body to a second posture covering a needle tip of the needle body, the protector comprising: a protector body formed by bending or curving an elastic plate-like member made of a metal material and including a first section formed with a first hole adapted to receive the needle body when the needle body is passed therethrough, a second section located on a proximal side of the first section and formed with a second hole adapted to receive the needle body when the needle body is passed therethrough, a third section adapted to connect one end of the first section with the second section, and a fourth section extending from the other end of the first section toward the distal side; and a cover portion including a needle tip receiving portion (32, 33) provided on a side of the fourth section of the protector body so as to cover the needle tip from the distal side during the second posture, and a needle body abutment portion that functions to prevent the needle tip receiving portion (32, 33) from covering the needle tip by abutment against an outer circumferential surface of the needle body during the first posture; characterized in that the protector being mounted on a needle body including also an enlarged-diameter section provided on a distal side of the main needle body and having an outer diameter greater than that of the main needle body; wherein the second section is provided with a tubular portion formed like a tube to project from a circumferential edge of the second hole toward a distal direction, and to permit the main needle body to pass therethrough while prohibiting the enlarged-diameter section from passing therethrough; and wherein the tubular portion has a minimum inner diameter, which is set to a value greater than an outer diameter of the main needle body and smaller than an outer diameter of the enlarged-diameter section, such that a gap is provided between an inner circumferential surface of the tubular portion and an outer circumferential surface of the needle body; and wherein the protector is shifted from the first posture in the distal direction relative to the needle body and the needle body abutment portion passes the needle tip, whereby the protector is deformed by an elastic force of the protector body so as to assume the second posture, and in the second posture, the tubular portion comes into abutment against the enlarged-diameter section to thereby prohibit the needle body from shifting toward the distal side. a protector body formed by bending or curving an elastic plate-like member made of a metal material and including a first section formed with a first hole adapted to receive the needle body when the needle body is passed therethrough, a second section located on a proximal side of the first section and formed with a second hole adapted to receive the needle body when the needle body is passed therethrough, a third section adapted to connect one end of the first section with the second section, and a fourth section extending from the other end of the first section toward the distal side; and a cover portion including a needle tip receiving portion (32, 33) provided on a side of the fourth section of the protector body so as to cover the needle tip from the distal side during the second posture, and a needle body abutment portion that functions to prevent the needle tip receiving portion (32, 33) from covering the needle tip by abutment against an outer circumferential surface of the needle body during the first posture; the protector being mounted on a needle body including also an enlarged-diameter section provided on a distal side of the main needle body and having an outer diameter greater than that of the main needle body; wherein the second section is provided with a tubular portion formed like a tube to project from a circumferential edge of the second hole toward a distal direction, and to permit the main needle body to pass therethrough while prohibiting the enlarged-diameter section from passing therethrough; and wherein the tubular portion has a minimum inner diameter, which is set to a value greater than an outer diameter of the main needle body and smaller than an outer diameter of the enlarged-diameter section, such that a gap is provided between an inner circumferential surface of the tubular portion and an outer circumferential surface of the needle body; and wherein the protector is shifted from the first posture in the distal direction relative to the needle body and the needle body abutment portion passes the needle tip, whereby the protector is deformed by an elastic force of the protector body so as to assume the second posture, and in the second posture, the tubular portion comes into abutment against the enlarged-diameter section to thereby prohibit the needle body from shifting toward the distal side.