A vehicle-to-vehicle communication device comprising: a mobile communication unit configured to transmit and receive a radio wave for direct communication of mobile communication; a threshold value storage unit configured to store a threshold value as to whether or not a predetermined control channel for vehicle-to-vehicle communication is an idle channel; a level detector configured to output a predetermined detection signal when a radio wave intensity of the predetermined control channel is larger than the threshold value; and a timer unit configured to start time counting in accordance with the detection signal output from the level detector and transmit a timer expiration signal to the level detector when the time counting for a predetermined time expires, wherein the mobile communication unit transmits the radio wave for the direct communication of the mobile communication when the level detector receives the timer expiration signal and the radio wave intensity of the predetermined control channel does not exceed the threshold value, characterised by : a storage unit configured to hold information associating information specifying a region with a frequency of the predetermined control channel used for vehicle-to-vehicle communication in the region; and a GPS receiving unit , wherein the mobile communication unit specifies a current region of a vehicle using latitude and longitude received by the GPS receiving unit , specifies a frequency of the predetermined control channel corresponding to the current region, and sets the reception frequency in the mobile communication unit to the specified frequency of the predetermined control channel. a mobile communication unit configured to transmit and receive a radio wave for direct communication of mobile communication; a threshold value storage unit configured to store a threshold value as to whether or not a predetermined control channel for vehicle-to-vehicle communication is an idle channel; a level detector configured to output a predetermined detection signal when a radio wave intensity of the predetermined control channel is larger than the threshold value; and a timer unit configured to start time counting in accordance with the detection signal output from the level detector and transmit a timer expiration signal to the level detector when the time counting for a predetermined time expires, wherein the mobile communication unit transmits the radio wave for the direct communication of the mobile communication when the level detector receives the timer expiration signal and the radio wave intensity of the predetermined control channel does not exceed the threshold value, characterised by : a storage unit configured to hold information associating information specifying a region with a frequency of the predetermined control channel used for vehicle-to-vehicle communication in the region; and a GPS receiving unit , wherein the mobile communication unit specifies a current region of a vehicle using latitude and longitude received by the GPS receiving unit , specifies a frequency of the predetermined control channel corresponding to the current region, and sets the reception frequency in the mobile communication unit to the specified frequency of the predetermined control channel. a storage unit configured to hold information associating information specifying a region with a frequency of the predetermined control channel used for vehicle-to-vehicle communication in the region; and a GPS receiving unit , wherein the mobile communication unit specifies a current region of a vehicle using latitude and longitude received by the GPS receiving unit , specifies a frequency of the predetermined control channel corresponding to the current region, and sets the reception frequency in the mobile communication unit to the specified frequency of the predetermined control channel. <EOS>