A control device for guided travel of an unmanned vehicle, in which the unmanned vehicle is guided to travel by receiving a signal sent from a GPS satellite by the unmanned vehicle, measuring its own vehicle position based on the signal, and controlling such that a positional shift between the vehicle position and a target point that is a passing point sequentially set on a target traveling course falls into an allowable range for controlling error, wherein a guidable range is set in advance such that a position measurement error is added to the allowable range for controlling error; the position measurement error is obtained based on position measurement accuracy information from the signal; the allowable range for controlling error is changed according to the obtained position measurement error; and control is performed such that the positional shift falls into the changed allowable range for controlling error.