PROBLEM TO BE SOLVED: To provide a medical instrument including a resin tube having favorable branch selectivity, while holding favorable pushability in an intricately-bent body cavity or an extremely narrow body cavity such as a vascular termination region.SOLUTION: A catheter 100 includes a medical instrument body (a catheter body 110) having a long resin tube (an outer tube 10), and the resin tube (the outer tube 10) includes a first area 12 consisting of a first resin member, and a second area 14 consisting of a second resin member as a resin member different from the first resin member and located at a proximal side with respect to the first area 12. A difference X between resin hardness of the first resin member measured at a normal temperature, and resin hardness of the first resin member measured after it is left in temperature environment of 38°C for a prescribed time is larger than a difference Y between resin hardness of the second resin member measured at the normal temperature, and resin hardness of the second resin member measured after it is left in the temperature environment of 38°C for the prescribed time.COPYRIGHT: (C)2016,JPO&INPIT【課題】複雑に屈曲した体腔、あるいは血管末端領域などの極細い体腔において、良好なプッシャビリティを維持しつつ、分岐選択性の良好な樹脂管を備える医療機器を提供する。【解決手段】カテーテル100は、長尺な樹脂管(外管10)を有する医療機器本体(カテーテル本体110)を有し、樹脂管(外管10)は、第一樹脂部材から構成される第一領域12と、第一樹脂部材とは異なる樹脂部材である第二樹脂部材から構成され第一領域12よりも近位側に位置する第二領域14とを有している。常温において測定された第一樹脂部材の樹脂硬度と、38℃の温度環境で所定時間放置された後に測定された第一樹脂部材の樹脂硬度との差異Xが、常温において測定された第二樹脂部材の樹脂硬度と、38℃の温度環境で所定時間放置された後に測定された第二樹脂部材の樹脂硬度との差異Yよりも大きい。【選択図】図1
