In an on-vehicle equipment for Dedicated Short-Range Communication (DSRC) in Intelligent Transport System (ITS), a priority sequence for switching local frequencies of f1 to f7 in correspondence with types of on-road equipment is previously set, the local frequencies are sequentially outputted at a predetermined cycle in accordance with the priority sequence, a received frequency signal is compared with a selected frequency signal, and when the received frequency signal is the same as the selection frequency signal, the local frequency corresponding to these is determined as a desirable communication frequency, and the communication frequency is fixed as being this local frequency with high efficiency.