A display unit is controlled to display guidance such as to instruct an operator to move a spindle up and down near the Z-axis position at which the tool is transferred between a grip and the spindle and to observe a lateral movement of the tip of a tool at the same time. Then, when the tip of the tool moves laterally, the display unit is controlled to display guidance to instruct the operator to raise the spindle and turn a turret so as to reduce the lateral movement of the tip of the tool.