PROBLEM TO BE SOLVED: To prevent effusion of a liquid medicine by restraining a gap from being made between a medical instrument and a seal member.SOLUTION: A syringe 1 for injecting a liquid medicine comprises a cylinder 2, and a seal member 4 that is brought into contact with an inner surface of the cylinder 2 and that can slide within the cylinder 2. The seal member 4 has a base body 40, and a film 6 that is stuck on the base body 40. The film 6 has a smooth area 63 in a part, which is brought into contact with the inner surface of the cylinder 2, of the seal member 4.
