As a metal material constituting a medical instrument such as a stent, it is easy to be absorbed into a living body after being implanted into a living body, but its absorption speed is not too fast, and has mechanical properties such as a predetermined high strength, A bioabsorbable magnesium alloy tube material excellent in workability in cold working or the like and a stent using the same are provided. SOLUTION: Al is contained in an amount of 1 to 3% by mass, Mn is contained in an amount of 1 to 2% by mass, Zn is contained in an amount of 1 to 10% by mass, Fe is less than 0.05% by mass, and O is less than 0.1% by mass. The balance is a magnesium alloy tube material composed of magnesium and 0.1% by mass or less of inevitable impurities, wherein the average crystal grain size of the base material is 1 to 20 μm, and the ratio of the wall thickness / tube outer diameter of the tube material Magnesium alloy tubing having a diameter of 0.02 to 0.5, a method for producing the same, a stent for vasodilation using the same, and a method for producing the same.【課題】ステントなどの医療器具を構成する金属材料として、生体内への埋入後に生体吸収がされやすく但しその吸収速度が速すぎず、かつ所定の高い強度などの機械的特性を有するとともに、冷間加工等での加工性に優れる生体吸収性マグネシウム合金管材とそれを用いたステントを提供する。【解決手段】Ａｌを１～３質量％、Ｍｎを１～２質量％、及びＺｎを１～１０質量％含有し、Ｆｅを０．０５質量％未満、及びＯを０．１質量％未満とし、残部がマグネシウムと０．１質量％以下の不可避不純物からなる組成のマグネシウム合金管材であって、母材の平均結晶粒径が１～２０μｍであり、前記管材の肉厚／管外径の比が０．０２～０．５であるマグネシウム合金管材とその製造方法、及びそれを用いてなる血管拡張用ステントとその製造方法。
