To implement filling non-thermostable medicine impossible to sterilize by heat in a medicine bag, at a low cost while assuredly keeping an aseptic condition.

The medicine filling device 20 filling the medicine in a medicine chamber 11 of the medicine bag 10 is provided with a medicine charging part 13 for charging the medicine and the medicine chamber 11 holding the medicine. The medicine charging part 13 is provided with a sealing member 13a sealing it. A nozzle 22 formed with a delivery port delivering the medicine in a tip neighborhood and a nozzle cover 23 housing the nozzle 22 so as to isolate it from outside air are provided particularly as means of delivering the medicine. The nozzle cover 23 is provided with an opening and closing means 26 opened and closed in a state airtightly connected with the medicine charging part 13. In the nozzle 22, at least its tip protrudes from the nozzle cover 23 when the opening and closing means 26 is opened, and it can reciprocate so as to penetrate the sealing member 13a.