Abstract: Machine tool with a driving spindle held in a carrier, an exchangeable machining head that can be coupled with the carrier and a tool spindle in the machining head that can be coupled with the driving spindle and adjustment and locking means on the carrier for locking the machining head onto the carrier. The machining head can be withdrawn from a magazine for machining heads by means of said adjustment and locking means and it can be coupled with and locked onto the machine tool and, after releasing, it can be brought into any desired angular position relative to the machine tool and locked again.