The present invention provides a before-use mixing container in which it is possible to perform a mixing operation for two types of medicinal solutions in its container independently of an uncovering operation for a cap or the like.The before-use mixing container including a movable body 1 which has a tube section 11, a ceiled cylindrical inner tube 13 which is consecutively installed upright on an inner surface of the tube section, that partitions the tube section into two upper and lower chambers, and a first opening portion 13b drilled in a ceiling plane 13a of the inner tube, and in which a first medicinal solution A is contained in the lower chamber, an adapter 3 which has a fit-in tube section 31 which is tightly fit into the upper chamber of the movable body to be assembled so as to be rotatable with respect to the movable body, a partition wall surface 35 which is provided on an inner surface of the fit-in tube section, and is tightly attached to the ceiling plane of the inner tube of the movable body, and a second opening portion 35a which is drilled in the partition wall surface so as not to overlap the first opening portion, and a container main body 4 which has a lower mouth tube section 42 tightly fit into the upper chamber of the adapter, to be assembled so as not to be rotatable with respect to the adapter, and in which a second medicinal solution B is contained, in the before-use mixing container, when the movable body is relatively rotated with respect to the container main body, the first opening portion and the second opening portion are overlapped.
