An automatic operation work machine comprising: a machine main body; a work implement mounted on the machine main body; an operation device that operates the work implement; an actuator that drives the work implement on a basis of a manual operation command signal generated by an operation of the operation device; a posture information measuring device (3a-3d) that acquires posture information which is information concerning posture of the work implement; and an automatic operation controller that generates an automatic operation command signal substituting for the manual operation command signal, and performs automatic operation for permitting the work implement to automatically perform a predetermined operation on a basis of the automatic operation command signal generated, characterized in that the automatic operation work machine further includes a terrain profile information measuring device that acquires terrain profile information surrounding the automatic operation work machine, and the automatic operation controller, when the automatic operation is finished, performs a detection process for detecting a ground contactable range in which the work implement can be placed on a basis of the terrain profile information acquired by the terrain profile measuring device, and, when the ground contactable range is detected, the automatic operation controller generates an automatic operation command signal to place the work implement in contact with the ground contactable range, whereas when the ground contactable range is not detected, the automatic operation controller generates an automatic operation command signal to place the work implement in a predetermined standby posture. a machine main body; a work implement mounted on the machine main body; an operation device that operates the work implement; an actuator that drives the work implement on a basis of a manual operation command signal generated by an operation of the operation device; a posture information measuring device (3a-3d) that acquires posture information which is information concerning posture of the work implement; and an automatic operation controller that generates an automatic operation command signal substituting for the manual operation command signal, and performs automatic operation for permitting the work implement to automatically perform a predetermined operation on a basis of the automatic operation command signal generated, characterized in that the automatic operation work machine further includes a terrain profile information measuring device that acquires terrain profile information surrounding the automatic operation work machine, and the automatic operation controller, when the automatic operation is finished, performs a detection process for detecting a ground contactable range in which the work implement can be placed on a basis of the terrain profile information acquired by the terrain profile measuring device, and, when the ground contactable range is detected, the automatic operation controller generates an automatic operation command signal to place the work implement in contact with the ground contactable range, whereas when the ground contactable range is not detected, the automatic operation controller generates an automatic operation command signal to place the work implement in a predetermined standby posture.