A machine tool includes a rotatable spindle, a spindle drive, a tool magazine, a tool changer including a rotating shaft, a rotating shaft drive motor, an angular position detector, a tool change arm having gripping units at both ends, and a controller. After interchanging a first tool mounted on the spindle and a second tool held in a tool pot, when rotating the tool change arm to an intermediate position, rotation of the spindle is started as soon as the second tool mounted on the spindle and the gripping unit are out of contact with each other.