A classifying device having two or more classifying passages is provided, the classifying device including a first classifying passage to which particle dispersion liquid is fed; plural discharge ports provided in the first classifying passage, the plural discharge ports including a discharge port of coarse particle dispersion liquid and a discharge port of fine particle dispersion liquid; a second classifying passage; and a connecting passage that transports the coarse particle dispersion liquid to the second classifying passage, wherein the discharge port of the coarse particle dispersion liquid is provided in more upstream part of the first classifying passage than the discharge port of the fine particle dispersion liquid.