A vehicle-mounted communication device comprising: a communication part configured to perform wireless communication; a judgment part configured to judge whether the communication part is in a wireless communicable state; and a judging timing determination part configured to stop the judgment part from operating of judging whether the communication part is in the wireless communicable state by operating the communication part, until a predetermined condition is satisfied, when the judgment part judges the communication part as being not in the wireless communicable state while an engine or motor of the vehicle is stopped; wherein the communication part includes a first communication part, which is configured to perform communication via a wireless communication network, and a second communication part, which is a GPS receiver configured to receive a GPS signal that is transmitted from one or more GPS satellites, wherein the judging timing determination part is configured to determine the predetermined condition based on at least one of a change in a reception electric field intensity of the wireless communication network before the engine or motor of the vehicle is stopped and a change in the number of the GPS satellites, from which the second communication part receives the GPS signal, before the engine or motor of the vehicle is stopped, and characterized in that the judging timing determination part is configured to stop the judgment operation of the judgment part until a condition surrounding the vehicle is judged as being changed, based on information that is obtained from the vehicle by means of at least one selected from the group consisting of an optical sensor, a photographing device, an impact detecting sensor and opening or closing a door or a window of the vehicle, when the change in the number of the GPS satellites, from which the GPS signal is received, before the engine or motor of the vehicle is stopped, is judged as being greater than a first threshold value. a communication part configured to perform wireless communication; a judgment part configured to judge whether the communication part is in a wireless communicable state; and a judging timing determination part configured to stop the judgment part from operating of judging whether the communication part is in the wireless communicable state by operating the communication part, until a predetermined condition is satisfied, when the judgment part judges the communication part as being not in the wireless communicable state while an engine or motor of the vehicle is stopped; wherein the communication part includes a first communication part, which is configured to perform communication via a wireless communication network, and a second communication part, which is a GPS receiver configured to receive a GPS signal that is transmitted from one or more GPS satellites, wherein the judging timing determination part is configured to determine the predetermined condition based on at least one of a change in a reception electric field intensity of the wireless communication network before the engine or motor of the vehicle is stopped and a change in the number of the GPS satellites, from which the second communication part receives the GPS signal, before the engine or motor of the vehicle is stopped, and characterized in that the judging timing determination part is configured to stop the judgment operation of the judgment part until a condition surrounding the vehicle is judged as being changed, based on information that is obtained from the vehicle by means of at least one selected from the group consisting of an optical sensor, a photographing device, an impact detecting sensor and opening or closing a door or a window of the vehicle, when the change in the number of the GPS satellites, from which the GPS signal is received, before the engine or motor of the vehicle is stopped, is judged as being greater than a first threshold value.