To provide a medicine-packed syringe of a simple structure, capable of preventing the attachment of the water to an injection nozzle and a Luer-lock in sterilizing treatment, and further surely preventing the contamination of the injection nozzle and the Luer-lock after the sterilizing treatment.

This medicine-packed syringe comprises a syringe 1A having the injection nozzle 21 and the Luer-lock 22 on its point, the medicine 9 sealed in the syringe 1A by a plunger 4 and a stopper 5, a space part 10 at a point side of the syringe 1A, having a by-pass structure, and a cap 7 for covering the injection nozzle 21 and the Luer-lock 22. The cap is made of rubber of specific hardness, and an inner diameter D2 of a cylindrical part of the cap 7 and a volume of an internal space of the Luer-lock 22 are respectively specified.