Abstract: A method for manufacturing an electronic apparatus comprises forming a quartz crystal tuning fork resonator having a fundamental mode of vibration and a second overtone mode of vibration each comprised of a flexural mode of an inverse phase, a series resistance R1 of the fundamental mode of vibration and a series resistance R2 of the second overtone mode of vibration. An amplification circuit is provided having a CMOS inverter, a feedback resistor, a negative resistance ?RL1 for the fundamental mode of vibration of the quartz crystal tuning fork resonator, and a negative resistance ?RL2 for the second overtone mode of vibration thereof. A feedback circuit is provided having the quartz crystal tuning fork resonator, a plurality of capacitors and a drain resistor. The quartz crystal tuning fork resonator is electrically connected to the CMOS inverter and the feedback resistor of the amplification circuit and to the capacitors and the drain resistor of the feedback circuit.