Micro-electro-mechanical system (MEMS) device including an internal anchor area

The invention provides an MEMS device. The MEMS device includes: a substrate, a proof mass, a spring, a spring anchor, a first electrode anchor, and a second electrode anchor, a first fixed electrode and a second fixed electrode. The proof mass is connected to the substrate through the spring and the spring anchor. The proof mass includes a hollow structure inside, and the spring anchor, the first electrode anchor, and the second electrode anchor are located in the hollow structure. The proof mass and the first fixed electrode form a first capacitor, and the proof mass and the second fixed electrode form a second capacitor. There is neither any portion of the proof mass nor any portion of any fixing electrode located between the first electrode anchor, second electrode anchor, and the spring anchor.