The present invention is one where, in a lead wire led-out type
crystal oscillator of constant temperature type for high stability, comprising: a
heat supply body that supplies heat to a
crystal resonator from which a plurality of lead wires are led out, to maintain the temperature constant; an oscillating element that constitutes an oscillating circuit together with the
crystal resonator; a
temperature control element that constitutes a
temperature control circuit for controlling the temperature of the crystal
resonator; and a circuit board for mounting the
heat supply body, the oscillating element, and the
temperature control element, and through which lead wires of the crystal resonator are passed through for mounting, the
heat supply body comprises: a
heat conducting plate which has through-holes for the lead wires and is mounted on the circuit board, and which faces, and is directly thermally joined to, the crystal resonator; and a
chip resistor for heating which is mounted on the circuit board adjacent to the
heat conducting plate, and is thermally joined to the
heat conducting plate. As a result, a lead wire led-out type
crystal oscillator of constant temperature type for high stability wherein the structure is simplified, and in particular the height dimension is reduced can be provided. Moreover, the present invention is a constant temperature type
surface mounting type
crystal oscillator which uses a crystal resonator for
surface mounting which is mounted on the circuit board together with the oscillating elements and temperature control elements, and is constructed such that the crystal resonator is arranged on a
ceramic substrate, and at least a
chip resistor for
heat generation and a highly temperature-dependent highly
heat sensitive element are arranged on the
ceramic substrate. The structure is such that the crystal resonator is arranged on one
principal plane of the
ceramic substrate, and the
chip resistor and the
temperature sensitive element are arranged on the other
principal plane of the
ceramic substrate, and the other
principal plane of the
ceramic substrate is positioned facing one principal plane of the circuit board, and heat conductive resin is interposed between the
chip resistor and the circuit board. A surface mounted
crystal oscillator of constant temperature type in which
miniaturization is advanced, and the structure is simplified, is provided.