A puncture needle cartridge 20 detachably mounted on a puncturing device body to form a puncturing device is provided with a needle body 21 having a puncturing portion 212a, and also with a casing 22 for housing the needle body 21 and having openings 223, 224 that are respectively formed in front of and behind the needle body 21. The needle body 21 is mounted so as to be movable between a retracted position, wherein the tip 212c of the puncturing portion is retraced in the casing 22, and an extended position, wherein the tip 212c of the puncturing portion is projected outward from the casing 22 by receiving a pressing force from the puncturing device body. The needle body 21 has a biasing means for biasing the needle body 21 from an extended position towards a retracted position. The puncture needle cartridge can be mass-produced at low cost, and enables a user to perform puncturing safely and easily.