To prevent occurrence of a defect such as deviation from a guide during travel after turning without any reduction in conveying efficiency of an automatic guided vehicle.

The automatic guided vehicle starts turning for matching the turning center of a vehicle body with the intersection (S3) when it reaches the intersection (S2). After turning is finished (S4:YES), a lateral deviation to the guide line of the vehicle after turning is found (S5). If the lateral deviation is not within a predetermined range (S6:NO), a low-speed travel distance for low-speed guided travel is decided based on the lateral deviation (S7). The automatic guided vehicle is guided to travel at a low speed only for the low-speed travel distance (A8). An attitude of the vehicle body is returned to normal one. Then, the vehicle is guided to travel at a high speed (S1). When the lateral deviation is within the predetermined range (S6:YES), the vehicle is guided to travel from the beginning.