(Abstract) The rotor geometry of a permanent magnet (PM) machine greatly affects the machine performance and therefore, it is very important to develop an initial conceptual structural topology of a PM rotor. We proposed an optimization method which is the combination of a topology optimization method and a method taking into account ease of manufacturing. This paper has manufactured an optimized rotor of a PM synchronous machine. It is also shown that when operating as a generator, the designed machine has 46 % higher output voltage than that of a commercialized one. The efficiency of the designed machine is improved by about 2 % comparing with the commercialized machine.