To provide a reliable machine controller, capable of automatically renewing a collision detecting threshold value set in advance according to a state of a loading machine such as a machine tool or an industrial robot, and minimizing a load upon collision without deteriorating the sensitivity of collision detection, even when friction and the like which acts on the machine changes.

The control unit has an initial value setting mode setting an initial value of the collision detecting threshold value, and a normal operating mode operating the loading machine by a normal operation pattern. The control unit comprises a control managing section 11 N-dividing the operation pattern and starting the operation in each operating section in the initial value setting mode, and holding the present disturbance estimated maximum value from a servo controlling portion 12; and the servo controlling portion 12 estimating a disturbance estimated value in each operating section, and transferring the maximum value to the control managing section 11 as the present disturbance estimated maximum value. In the normal operating mode, the control managing section 11 automatically renews a present collision detecting threshold value according to the disturbance estimated value and the present collision detecting threshold value.