A projector includes a light-emitting device, a color wheel, a notch filter, a switching device, and a light controller. The light-emitting device is configured to emit a light. The color wheel is disposed on a path of the light and is configured to produce lights with different color wave bands. The notch filter has two cut-off waveband, and each is located between adjacent two of the color wavebands. The switching module is configured to move the notch filter to or away the path of the light. The light controller is electrically connected to the light-emitting device and the switching module, and is configured to control an intensity of the light emitted by the light-emitting device.