An electromagnetic wave absorber (1a) includes a resistive layer (10), an electrically conductive layer (20) and a dielectric layer (30). The electrically conductive layer (20) has a sheet resistance lower than a sheet resistance of the resistive layer (10). The dielectric layer (30) is disposed between the resistive layer (10) and the electrically conductive layer (20). The electromagnetic wave absorber (1a) has a first slit (15). The first slit (15) extends, in the resistive layer (10), from a first principal surface (10a) distal to the dielectric layer (30) toward the dielectric layer (30) in a direction perpendicular to the first principal surface (10a) and divides the resistive layer (10) into a plurality of first blocks (17). Each of the first blocks (17) has a minimum dimension (D1) of 2 mm or more at the first principal surface (10a).