A MEMS device of an aspect of the present invention including a MEMS element includes a first lower electrode provided on a substrate, a first insulator which is provided on the upper surface of the first lower electrode, and has a first thickness, and a movable first upper electrode supported by an anchor in midair above the first lower electrode, and a capacitance element includes a second lower electrode provided on the substrate, a second insulator which is provided on the upper surface of the second lower electrode, and has a second thickness, and a second upper electrode provided on the second insulator, wherein the second thickness is less than the first thickness.