<;P>;PROBLEM TO BE SOLVED: To actualize a balloon catheter which has a diamond-like membrane, is hard to slip and accurately expands a lesion region. <;P>;SOLUTION: The balloon catheter is provided with a balloon body 11 and a diamond-like membrane 12 formed at its external surface. The silicon content of the diamond-like membrane 12 is 5 atomic% or more and 35 atomic% or less. <;P>;COPYRIGHT: (C)2009,JPO&INPIT