A coating apparatus includes a chamber device and a transporting device. The chamber device defines two coating chambers, two parallel coating channels, and a transportation channel communicating with the coating channels. The coating chambers are separated from each other. The coating chambers and the coating channels are alternately arranged. Each coating chamber defines at least one coating slot communicating with the respective coating channel. The transporting device includes a shaft rotatable with respect to the chamber device and a carrying board fixed on the shaft. The shaft is axially movable in the transportation channel. The carrying board is receivable in each of the coating channels for exposing a substrate to the corresponding coating chamber via the associated coating slot. The carrying board is rotatable about the shaft in each of the coating channels and jointly movable with the shaft in and along the transportation channel between the coating channels.