A MEMS device including a fixed member and a movable member supported via a resilient body. The MEMS device includes an impact alleviation mechanism provided at a position where the movable member and the fixed member collide during operation. The impact alleviation mechanism includes a stopper provided to either the fixed member or the movable member and that protrude to be parallel between sides of the two members with at least one side edge fixed to the respective member. Moreover, the impact alleviation mechanism includes an elongate protruding member provided on the other of the fixed member and the movable member. The elongate protruding member and the stopper are configured such that as collision force increases between the movable member and the fixed member during operation, an abutment area of an outer edge position of the elongate protruding member approaches the fixed side edge of the stopper.