To provide a means which can prevent medicines from absorbing moistures particularly in a batch type medicine producing line in which a freeze- drying process is used.

In a container 1 to store ampules 3 each charged with liquid in closed conditions, a plug 11 is put into each opening 10 formed in the surface of the container 1. In such a condition that the plug 11 is not completely driven into the opening 10, the container 1 communicates with the outside through the opening 10, while in a condition such that the plug 11 is completely driven into the opening 10, the interior of the container 1 is sealed off. By reducing the moisture outside the container 1 under conditions that the plug 11 is not completely driven into the opening, liquid filled into the ampules 3 can be dried. On the other hand, under conditions that the plug is fully driven in, the interior of the container 1 can be held in a moisture reduced condition.