PURPOSE: To reduce the temperature difference between an IC which incorporates a temperature sensor and a piezoelectric oscillator by arranging the IC and piezoelectric oscillator on the same metallic plate.

CONSTITUTION: The metallic plate 7 adhered onto a circuit board extends avoiding the connection wiring pattern between the IC9 incorporating the temperature sensor and piezoelectric oscillator 8. Then, the IC9 and oscillator 8 are die-attached onto the metallic plate 7. Then, a wire for bonding is bonded to each wiring pattern except the metallic plate 7. Further, the IC9 is molded with a molding material 10. A lead is bent and connected to a wiring pattern from the IC9 after the oscillator 8 is adhered to the metallic plate 7. Consequently, the temperatures of the IC9 and oscillator 8 approximate the same temperature by the excellent heat conduction of the metallic plate. Thus, the temperature difference between the IC incorporating the sensor and piezoelectric oscillator is reduced.