The disclosure relates to a micro-electromechanical system (MEMS) device having an electrical insulating structure. The MEMS device includes at least one moving part, at least one anchor, at least one spring and an insulating layer. The spring is connected to the anchor and to the moving part. The insulating layer is disposed in the moving part and the anchor. Each of the moving part and the anchor is divided into two conductive portions by the insulating layer. Whereby, the electrical signals of different moving parts are transmitted through the insulated electrical paths which are not electrically connected.