A liquid leakage between a needle and a needle port is prevented. To this end, a guide section, a passage section, and a tapered section are provided in an in-port path of a needle port. The guide section has an inside diameter larger than the outside diameter of a body of a needle. The passage section has an inside diameter smaller than the outside diameter of the body of the needle and larger than the tip diameter of a tapered portion of the needle. The tapered section connects the guide section and the passage section. The taper angle θ2 of the tapered section is set to be larger than the taper angle θ1 of the tapered portion of the needle, and the width w of the tapered section is set to be smaller than half the difference between the outside diameter of the body and the tip diameter of the needle.