A renewable adsorbent enabling to adsorb cesium selectively and efficiently, and to reuse cesium by eluting adsorbed cesium, and its manufacturing method are provided. Polyethylene (PE)/polypropylene (PP) based non-woven fabric may be exposed with electron beam, PE/PP based non-woven fabric to which electron beam was exposed is contacted to the monomer solution containing acrylonitrile (AN), dimethyl sulfoxide (DMSO), Tween80 (polyoxyethylene sorbitan monooleate) as a surfactant, and AMP (ammonium molybdophosphate n-hydrate) as an inorganic ion exchanger, and then the inorganic ion exchanger (AMP) is supported directly by the non-ionic graft chain.