Provided is a novel porous cellulose medium that can efficiently separate a large target molecule in a calibration standard. A porous cellulose medium including a porous cellulose particle having a particle size from 1 to 600 μm, wherein, in sieving the porous cellulose medium for classification and using a fraction corresponding to aperture openings between 53 μm and 106 μm as a support for size exclusion chromatography, a polyethylene oxide standard is run through size exclusion chromatography with pure water as a mobile phase, and a weight average molecular weight Mw and a gel partition coefficient Kav of the polyethylene oxide standard satisfy Relationships (A) and (B) above: in a case where 4.80≤log Mw≤5.50,Kav>−0.445×log Mw+2.55  (A) in a case where 5.75≤log Mw,0≤Kav