The present invention provides a before-use mixing container in which it is possible to easily perform a mixing operation for two types of medicinal solutions and it is not until a mixing operation is performed that a medicinal solution is extracted for use from inside a container. The before-use mixing container includes an adapter 2 having an outer tube 21 installed vertically from an apical wall 22 and an inner tube 23, a container main body 1 having a mouth tube section 12 fit at an outside of the outer tube 21, to be assembled so as not to be rotatable with respect to the adapter, a guide cap 3 having a fit-in tube section 31 into which the outer tube 21 is pressed to fit at an inside thereof, to be assembled so as to be rotatable with respect to the adapter, a cap 4, and a movable plug 5 that tightly plugs a lower end opening portion of the inner tube 23, in which the movable plug 5 has an airtight-cap section 53 for tightly plugging the lower end opening portion of the inner tube 23, and an axial body 54 extended upward from the airtight-cap section to be inserted through a rotation restricting hole 25a formed in the adapter 2, and in a state in which a leading end portion of the axial body is brought into contact with an extracting hole 35c formed in the guide cap 3, an end portion of the axial body is screwed in axial body mounting sections 36 and 36 provided inside the guide cap 3.
