A torsional MEMS device is disclosed. The torsional MEMS device includes a support structure, a platform, and at least two hinges, which connects the platform to the support structure. The platform has an active area and a non-active area. A plurality of sacrificial elements is disposed in the non-active area. If the resonant frequency of the torsional MEMS device is less than a predetermined standard resonant frequency of the torsional MEMS device, at least one sacrificial element is removed to reduce the total mass of the torsional MEMS device, and so as to increase the resonant frequency of the torsional MEMS device.