A resonator with a microeletromechanical system structure has a transistor with a gate electrode, a capacitor with an upper and lower electrode, a substrate, a first and second structure of the microelectromechanical system structure, a first silicon layer of the first structure and the upper electrode formed above the substrate, a second silicon layer of the second structure and the gate electrode unit formed above the substrate, and an insulating film formed above the capacitor and the transistor, the insulating film having an opening for placement of the second structure.