[Object] To provide a medical instrument capable of more effectively inhibiting a cracking and separation than conventional ones.
[Solution Means] A stent comprising a substrate layer 10 of which at least the surface is composed of a metal material, a carbon compound layer 12 that is formed so as to coat the surface of the substrate layer 10 and that contains at least one metal element, a first DLC layer 14 that is formed so as to coat the surface of the carbon compound layer 12 and that is free of fluorine, and a second DLC layer 16 that is formed so as to coat the surface of the first DLC layer 14 and that contains fluorine. The stent being constituted to satisfy the relationship defined by the expression of "A1>A2>A3", wherein A1 is a surface free energy of the carbon compound layer 12, A2 is a surface free energy of the first DLC layer 14, and A3 is a surface free energy of the second DLC layer 16.