A wafer rotating apparatus includes a base, a carrying device, a first shaft gear, a power unit, a roller, a second shaft gear and a driving assembly. The base has an accommodating space which the carrying device is disposed in to accommodate the wafer. The first shaft gear is disposed on a side surface of the base. The power unit is assembled to a top of the base and connected to the first shaft gear. The roller is located under the carrying device and supports an edge of the wafer. The second shaft gear is disposed on the side surface of the base and connected to the roller. The driving assembly is connected between the first shaft gear and the second shaft gear. The power unit provides a power through the first gear, the driving unit and the second shaft gear to drive the roller to rotate the wafer.