The invention relates to a drive device for driving a drill rod having a drive means with a rotary drive and a vibration drive for driving an output shaft in a rotating and axially vibrating manner and an adapter means which is coupled with the output shaft and comprises an outer adapter for connecting an outer rod and an inner adapter for connecting an inner rod. The outer adapter is adapted to transmit the rotational movement and the axially vibrating movement of the output shaft to the outer rod. The inner adapter is supported in an axially displaceable and spring-mounted manner in the outer adapter. The invention further relates to a method for operating a drive device.