Abstract: An electromagnetic wave absorber including: a porous substrate having a large number of pores piercing the porous substrate; and an absorbent film formed on circumferential surfaces of the pores and constituted by a mixture of an electromagnetic wave absorbing filler and an electromagnetic wave absorbing high-molecular material, wherein the pores are not blocked with the absorbent film so that the pores are permeable to gas. Accordingly, the electromagnetic wave absorber is high in electromagnetic wave absorbing performance, can be made thin and lightweight and is so excellent in reliability that the electromagnetic wave absorbing performance can be offered over a very broad range.