The present invention provides a production method with which a porous carrier can be allowed to evenly carry a polysaccharide derivative. That is, the present invention provides a method of producing an enantiomeric isomer-separating filler, including bringing a porous carrier and a solution of a polysaccharide derivative into contact with each other through a stirring operation in a stirring device, to allow the porous carrier to carry an optically active polymer compound, in which: a two-axis vertical stirring device is used as the stirring device; and the porous carrier is allowed to carry the polysaccharide derivative in a carrying amount of 23 mass % or more.