The present invention relates to a display apparatus with pixels, wherein each pixel includes a switching device, a micro-electro-mechanical system (MEMS), and a gray scale control device. The switching device can be connected to a gate line and a data line to output a corresponding data signal in response to a gate signal. The MEMS may be connected to an output electrode of the switching device to transmit or block light in response to the corresponding data signal. The gray scale control device may be coupled to the output electrode of the switching device to control a time interval during which the corresponding data signal is applied to the MEMS. Accordingly, each pixel may display a desired gray scale.