We have developed a tilling robot that can recognize its own position and heading, while performing unmanned tilling at almost the same work rate as manual work. The tilling robot is composed of navigation systems for positioning and heading, a robotized vehicle, a controller, and an operation software. A geomagnetic sensor (TMS) is utilized for the navigation system for heading. The operation software consists of teaching, path planning, vehicle controlling, self-diagnosis, and abnormality alarming sections. We found that the tilling robot can perform unmanned tilling operations over a whole field area of 50 a with almost the same efficiency and accuracy as manual work.