The electrostatic device comprises: a fixed portion, a movable portion and an elastic support portion for elastically supporting the movable portion, which are formed on the same substrate; a first glass
package, which is anodically bonded to one of the front and back surfaces of the substrate in a state where the fixed portion and the elastic support portion are separated from each other; and a second glass
package, which is anodically bonded to the other of the front and back surfaces in a state where the fixed portion and the elastic support portion are separated from each other, and a
closed space for arranging the movable portion is formed between the second glass
package and the first glass package, an
electret is formed on at least a portion of the fixed portion and the movable portion, and a first
electrode connected to the fixed portion and exposed on the outer surface of the second glass package, and a second
electrode connected to the elastic support portion and exposed on the outer surface of the second glass package are formed on the second glass package.