PURPOSE: To ensure the highly efficient and highly accurate autonomous traveling of a vehicle by measuring the position of its own vehicle based on the position measurement information acquired by a satellite and the correction information on the position measurement result of a known point and also based on the traveling history started at a reference position and calculating the present position of its own vehicle by averaging those measured positions.

CONSTITUTION: An estimated navigation position detecting part 52 accumulates the distance traveled obtained by integrating the vehicle speed detected by a wheel encoder 5 in response to the change of the traveling direction detected by an earth magnetism sensor 4 and calculates a traveling history started at a reference point to measure the position of its own vehicle. A D-GPS position detecting part 53 measures the position of its own vehicle based on the navigation message sent from a group 70 of GPS satellites and the differential information given from a fixed station 30. A traveling control part 56 calculates the difference of position measurement data between both parts 53 and 52 as the position correction value. Then the part 56 calculates the present position of the vehicle based on the value obtained by averaging the position correction value and performs and autonomous traveling control of the vehicle.