To collect particles included in aerosol in the classified state in each particle size.

This nanoparticle classification collection device 1 is formed to enclose a sheath gas passage 9 by plane parts 3, 5 installed together in the vertical direction in mutually parallel at a fixed interval L and a shell part 7 for fixing both plane parts. The plane part 3 includes an aerosol introduction port 13 for blowing out the aerosol charged by a charging device 11 into the sheath gas passage 9. The aerosol introduction port 13 is a slit 23 whose opening shape facing to the sheath gas passage is extended in the horizontal direction in order to allow the aerosol to flow as a laminar flow in the sheath gas passage 9 which is a classification part. The plane part 5 is equipped on the sheath gas passage 9 side with a collection electrode 15 as a conductive flat plate for collecting the aerosol in the classified state in each particle size. The aerosol can be collected in the classified state in each particle size by the collection electrode 15, by applying a direct-current electric field orthogonal to the sheath gas flow to the interval between both plane parts.