PROBLEM TO BE SOLVED: To provide a stylet, the protrusion and base plate of which can be rapidly dissolved by using moisture supplied from the inside of the skin when the skin is punctured with the stylet.SOLUTION: A stylet includes a base plate 2, and a needle-like protrusion 1 that is formed on one surface (front side 2S) of the base plate 2. The base plate 2 has a recess 3 on the one surface (front side 2S). The protrusion 1 and the base plate 2 are formed of a water-soluble material. A root part of the protrusion 1 and an outer peripheral part of the recess 3 are brought into contact with each other.SELECTED DRAWING: Figure 1【課題】本発明は、針状体の穿刺時に皮膚内より供給される水分を用いて、針状体の突起部及び基板を速やかに溶解可能な針状体を提供することを目的とする。【解決手段】基板２と、基板２の一方の面（表面２Ｓ）に形成された針状の突起部１とを備え、基板２は、一方の面（表面２Ｓ）に凹部３を有し、突起部１及び基板２が水溶性材料で形成されており、突起部１の根元部分と凹部３の外周部とが接触している。【選択図】 図１
