Medical instrument of the present invention includes a substrate, in which cells are in contact with or held on a surface of the substrate, and at least the surface of the substrate which holds the cells is formed of a fluorine-containing cyclic olefin polymer which contains a repeating structure unit represented by Formula (1), wherein in Formula (1), at least one of R 1 to R 4 is fluorine, an alkyl with 1 to 10 carbon atoms which contains fluorine, an alkoxy with 1 to 10 carbon atoms which contains fluorine, or an alkoxyalkyl with 2 to 10 carbon atoms which contains fluorine, R 1 to R 4 are selected from hydrogen, alkyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, or alkoxyalkyl with 2 to 10 carbon atoms in a case where R 1 to R 4 are groups which do not contain fluorine, R 1 to R 4 may be the same as or different from each other, and R 1 to R 4 may be bonded to each other to form a cyclic structure.本發明的醫療器材具備基材且使細胞接觸或保持於所述基材的一面上，並且所述基材的至少保持細胞的所述一面是由含有下述通式(1)所表示的重複結構單元的含氟環狀烯烴聚合物所構成。(式(1)中，R1~R4中，至少一個為氟、含氟的碳數1~10的烷基、含氟的碳數1~10的烷氧基或含氟的碳數2~10的烷氧基烷基。於R1~R4為不含氟的基團的情形時，R1~R4是選自氫、碳數1~10的烷基、碳數1~10的烷氧基或碳數2~10的烷氧基烷基中。R1~R4可彼此相同亦可不同。R1~R4亦可相互鍵結而形成環結構)
