A highly flexible delivery device (2) for a stent graft (6) particularly for deployment into the thoracic arch of a patient. The delivery device has a distal handle (7), a pusher catheter (4) extending proximally from the handle to a proximal nose cone dilator (11), a guide wire catheter (3) extending from the proximal nose cone dilator to the pusher catheter. To give flexibility the guide wire catheter comprises a nitinol tube, the nose cone dilator has a high flexibility and the pusher catheter has a graded flexibility being more flexible at its proximal end than at its distal end. The graded flexibility can be provided by joined segments (4a, 4b and 4c) of different flexibility or by a inner metal tube (72) to give rigidity over some of the length. Alternatively the graded flexibility can be provided by tapering the wall thickness (80, 80a) of the pusher catheter.
