PROBLEM TO BE SOLVED: To provide an automatically travelling field work machine having a simplified control mechanism for shifting from a work travelling mode to a non-work travelling mode.SOLUTION: A field work machine includes: a travelling machine body 1; a field work device 2 for executing a farm work on a field: a GPS module 5 for outputting positioning data; a route calculation section 73 for calculating a travelling route; an automatic travelling control section 61 for allowing the travelling machine body 1 to automatically travel along the travel route on the basis of the positioning data and the travelling route; a non-work travelling discrimination section 75 for determining travelling on non-work route by dividing the travelling route between a work travelling route and a non-work travelling route; and an automatic travelling prohibition section 76 for prohibiting automatic travelling by the automatic travelling control section 61 when the travelling is determined to be on the non-work travelling r
