To provide a puncture needle cartridge which can prevent a used lancet from being reused. A puncture needle cartridge 101 includes a puncture needle holder 102 configured to be cylindrical, placed on an outer circumferential surface of a lancet body 104, and provided with an opening 102a through which a puncture needle 201 is allowed to protrude, and a protective cap 103 adapted to cover and protect the opening 102a and configured to be separable from the puncture needle holder 102. The protective cap 103 includes a base 103a adapted to cover the opening 102a when the protective cap 103 is joined and a pair of raised walls 203 which protrude from the base 103a toward the puncture needle holder 102 and whose tip portions are placed facing each other. Tip portions of the raised walls 203 pinch the puncture needle holder 102 by spreading against elastic deformation when the protective cap 103 is joined to the puncture needle holder 102, and when the protective cap 103 is separated from the puncture needle holder 102, a space between the tip portions becomes smaller than outside diameter of the puncture needle holder 102 dues to elastic deformation.
