A leaky coaxial cable is arranged to meander on a ceiling of an indoor space where a wireless LAN is to be worked. One end of the leaky coaxial cable is connected to a wireless base station unit and the other end thereof is connected to a terminator. The wireless base station unit makes wireless communication with a wireless terminal unit through the leaky coaxial cable by modulation and demodulation in orthogonal frequency division multiplex modulation (OFDM).