A separation method including the steps of defining a batch process for handling a batch of a mobile phase containing a material to be separated, providing a separation device having a separation column composed of a plurality of N columns (1, 2) each provided with a stationary phase, sequentially supplying said mobile phase to said columns (1, 2) provided with said stationary phase, wherein the stationary phase has a total volume capable of processing an entire volume of said mobile phase containing said material to be separated, the separation column being replaceable, wherein a usage count of the stationary phase reaches a lifetime count by said batch process, recovering the material to be separated from the stationary phase after processing the entire volume of the mobile phase, and replacing the used separation column after the capture step, a plurality of pipes are respectively connected to each of the plural columns (1, 2); a plurality of switching valves are respectively provided on the plurality of pipes; and a control device controls communications between the pipes by the plurality of switching valves, wherein the number N of columns (1, 2) necessary to continuously process the volume of said mobile phase of the defined batch is determined by the following equation: N ≥ T 1 + T 2 + T 3 + T 4 + T 5 / T 2 where N is the minimum integer number of columns (1, 2) satisfying the above equation, T1 is an equilibration time of the columns, T2 is an adsorption time of the material to be separated, T3 is a washing time, T4 is an elution time of the material to be separated and T5 is a regeneration time of the columns (1, 2), wherein the volume Vc of each of the columns (1, 2) is determined according to Vc ≥ Ct * Vb / Am * R * N wherein Ct is the target material concentration in a culture solution, Vb is the volume of the culture solution of said batch, Am is the dynamic adsorption amount of the target material per unit volume of column, N is said number of columns (1, 2) and R is the number of column (1, 2) reuse, said number R constituting said lifetime count. defining a batch process for handling a batch of a mobile phase containing a material to be separated, providing a separation device having a separation column composed of a plurality of N columns (1, 2) each provided with a stationary phase, sequentially supplying said mobile phase to said columns (1, 2) provided with said stationary phase, wherein the stationary phase has a total volume capable of processing an entire volume of said mobile phase containing said material to be separated, the separation column being replaceable, wherein a usage count of the stationary phase reaches a lifetime count by said batch process, recovering the material to be separated from the stationary phase after processing the entire volume of the mobile phase, and replacing the used separation column after the capture step, a plurality of pipes are respectively connected to each of the plural columns (1, 2); a plurality of switching valves are respectively provided on the plurality of pipes; and a control device controls communications between the pipes by the plurality of switching valves, wherein the number N of columns (1, 2) necessary to continuously process the volume of said mobile phase of the defined batch is determined by the following equation: N ≥ T 1 + T 2 + T 3 + T 4 + T 5 / T 2 where N is the minimum integer number of columns (1, 2) satisfying the above equation, T1 is an equilibration time of the columns, T2 is an adsorption time of the material to be separated, T3 is a washing time, T4 is an elution time of the material to be separated and T5 is a regeneration time of the columns (1, 2), wherein the volume Vc of each of the columns (1, 2) is determined according to Vc ≥ Ct * Vb / Am * R * N wherein Ct is the target material concentration in a culture solution, Vb is the volume of the culture solution of said batch, Am is the dynamic adsorption amount of the target material per unit volume of column, N is said number of columns (1, 2) and R is the number of column (1, 2) reuse, said number R constituting said lifetime count.