[Object]To provide an absorbent article and an absorbent body having excellent absorption performance.[Solution]The present invention provides an absorbent body having at least two or more layers, the absorbent body comprising: a water absorption layer having a water absorption region where a water absorbent resin powder is disposed and a thickness-direction-penetrating opening region and a layer having a diffusion region where a diffusibility improvement material having an under-load liquid passing rate of 15 seconds or less is disposed, as a lower layer of the water absorption layer, wherein the lower layer has the diffusion region disposed at least a part of a portion located below the opening region.