22 23 which determine the depth of pulverizing soil with the rotor disks 7 by touching the surface of the land 36 the depth of pulverizing soil is preferably 40 to 60 cm because almost all the antipersonnel mines had been laid within the said depth to the front of the stabilizer 3 a sensor or a metal detector 25 is attached for detecting an antitank mine 24 laid under the ground in the land 36 the sensor 25 is arranged to be able to scan at least the area corresponding to the breadth of the stabilizer 3 tractor 1 when a detection signal from the sensor 25 is outputted to a control section 38 of the tractor 1 the control section 38 cuts off i e disengages a main clutch 27 between the engine 30 and the crawler 31 through a relay circuit 26 and stops the advance of the tractor 1 keeping the engine 30 idling the antitank mine 24 detected by the sensor 25 is disposed by a previous traditional method when the disposal of the mine 24 has been finished the tractor 1 is advanced again by the remote control transmitter 29 since the antitank mine 24.