To provide an electromagnetic wave absorber for shielding electromagnetic waves of a specific frequency reliably by a simple structure.

Two or four triangular punched portions 14 having their individual apexes opposed to each other are formed axially symmetrically with respect to either one symmetry axis 13 or an orthogonally symmetry axis imagined on a plane of metal foil 12, thereby forming a slotted bow-tie antenna element 15 around the punched portion. The antenna element 15 may have feeding points short-circuited or opened from each other.