A drug solution transfer method includes step S1 of inserting a needle into a drug solution container through a rubber stopper and sucking drug solution in the drug solution container, step S2 of checking whether or not a solution collection inlet at a tip of the needle has shifted into the rubber stopper upon extracting the needle from the drug solution container, step S3 of pulling a plunger of a syringe provided with the needle so that an inside of the needle and an inner space of the syringe have negative pressure, and step S4 of relatively shifting the needle along with the syringe to be distant from the drug solution container so as to extract the solution collection inlet of the needle from the rubber stopper.
