A resonance device that includes a MEMS substrate including a resonator, an upper cover, and a bonding portion that bonds the MEMS substrate to the upper cover to seal a vibration space of the resonator. The bonding portion includes a eutectic layer composed of a eutectic alloy of germanium and a metal mainly containing aluminum, a first titanium (Ti) layer, a first aluminum oxide film, and a first conductive layer consecutively arranged from the MEMS substrate to the upper cover.