An object of the present invention is to improve the transportation efficiency of an automatic transport system for transporting an article. In order to attain the above object, the automatic transport system of the present invention comprises a front detecting device which detects an obstruction in a non-contact state in an area through which an automatic transport vehicle passes and a projection surface of said automatic transport vehicle, and when said front detecting device detects the obstruction in said area, the running speed of said automatic transport vehicle is reduced or said automatic transport vehicle is stopped.