A radio wave absorber unit includes two or more molded bodies in a pyramid or wedge shape whose radius at the tip end is from 0.5 mm to 7.5 mm and a base. A radius at the trough between adjacent molded bodies is 7.5 mm or less. A unit including molded bodies and the base is integrally formed from propylene-based conductive expanded beads. The bases of adjacent units are connected by fitting their recessed and raised portions to each other. The expanded bead size is in the range from 2 mm to 10 mm, and beads with two or more different bead diameters can be used. A hollow molded body can be formed by providing a hollow structure inside.