A drilling machine with an automatic tool changer (A.T.C.) comprising a driving motor for a spindle head and a tool magazine rotatably supported by the spindle head and provided with a plurality of tool arbors for holding tools, one of the tools being interchanged with another of the tools by intermittent rotation of the tool magazine, and wherein the tool arbors are supported for swinging movement between a protrusion position and a retraction position so as not to obstruct the machining operation.