In a method for manufacturing a quartz crystal unit, a metal film is formed on a quartz crystal wafer which is then etched to form a quartz crystal tuning fork resonator having first and second tines vibratable in flexural and fundamental modes. A groove is chemically etched in a first main surface of both tines such that a first surface of the groove is opposite a first side surface of the corresponding tine. The width of the groove is greater than a distance in the width direction from the groove first surface to the first side surface of the corresponding tine. An electrode is formed on each groove first surface and on the first side surface of both tines with the electrode on the groove first surface of the first tine having the same electrical polarity as the electrode on the first side surface of the second tine.