The present invention provides an absorber and a disposable absorbent article which prevent deformation of the absorber due to twisting and have improved absorbing speed. The absorber includes an assembly at least having assembled fibers and a sheet member. The sheet member is made of a liquid-permeable nonwoven fabric, covering an upper surface and left and right edges of the assembly, and also covering regions at least in the vicinity of the left and right edges on a lower surface of the assembly. The sheet member is adhered to the assembly at least in the vicinity of the left and right edges on the lower surface of the assembly.