To reduce multipaths in indoor radio communication by providing a radio wave reflecting suppressor at a reflective spot based on geometrical optics where a radio wave to be transmitted and received between a base station and a terminal station provided in an installation space is reflected according to the principle of geometrical optics on the surface composing the installation space.

A radio communication installation space A is constituted in an almost box type space surrounded by a ceiling 1, a floor 2 and wall surfaces 3, 4, 5 and 6. A base station antenna 7a, which is provided to a base station 7 for transmitting a radio wave, is provided on the ceiling 1 side in the space. A terminal station antenna 8a, which is provided to a terminal station for receiving the radio wave transmitted from the base station, is provided on the floor side 2. When the radio wave transmitted from the base station antenna 7a undergoes four reflections until it is received by the terminal station antenna 8a, the first reflection of the radio wave transmitted from the base station 7a occurs at a reflective spot based on geometrical optics 9.