Divemaster is the first professional level in the PADI system. A PADI Divemaster is a professional dive guide who can also conduct some other programs, such as the Scuba refresher. He can also assist instructors in other courses and programs.
To begin the DM course, you have to be certified as a RD or equivalent, 60 logged dives upon completion of the course.
Please note that a certification fee will also need to be paid directly to PADI