An electromagnetic screen (1) comprises a plurality of antennas (4) each of which reflects an electromagnetic wave having a specific frequency. The plurality of antennas (4) are arranged so as to constitute a pattern. Each of the antennas (4) has three segment-shaped first element parts (4a) and three segment-shaped second element parts (4b). The three first element parts (4a) radially extend from the center of the antenna (4) by substantially the same length such that any two of the three first element parts (4a) form an angle of 120° with each other. Each of the second element parts (4b) are connected to an outer edge of a corresponding one of the first element parts (4a).