A liquid storage chamber having a plurality of stages formed by horizontal partition plates which divide the space in the tank into a plurality of storage chambers. The partition plates have openings at their alternating ends so that the liquid supplied to the tank can flow down through the successive liquid storage chamber in a serpentine manner. The liquid storage chamber further has an opening flow setting plate having a multiplicity of liquid passage ports and disposed in each opening for making the liquid flow laminar through each opening and a storage chamber flow setting plate having a multiplicity of flow passage ports and disposed in each liquid storage chamber for making the liquid flowing horizontally in each liquid storage chamber flow in the form of a laminar flow. Consequently, liquids introduced into the tank exhibiting a chromatographic concentration distribution are stored in such a manner as to avoid the mixing of liquids of different components and concentrations due to stirring and convection, in the order of introduction to the tank, and are discharged in the same order as the introduction to the tank.
