A piezoelectric device includes a piezoelectric resonator including a piezoelectric resonator element, a package for accommodating the piezoelectric resonator in a cavity thereinside, a lid for airtightly sealing the cavity inside the package, a package base included in the package, and an external terminal formed on a bottom surface of the package base; a circuit element stacked together with the piezoelectric resonator to be electrically connected thereto; a wiring substrate having the circuit element mounted on a first surface thereof and a mounting external terminal provided on a second surface thereof, a connecting member arranged in a periphery of the circuit element mounted on the first surface of the wiring substrate to electrically and mechanically connect the wiring substrate to the external terminal of the piezoelectric resonator; and a molded portion made of a molding member that is formed from the first surface of the wiring substrate up to at least a position higher than an upper end surface of the package base of the piezoelectric resonator, the molded portion covering the first surface of the wiring substrate, the package base of the piezoelectric resonator, the external terminal formed on the bottom surface of the package base, the circuit element, and the connecting member, whereas at least a part of a marking region on the lid being exposed from the molded portion.