A quartz crystal resonator includes a quartz crystal resonator element, a thermistor, and a package base having a first principal surface and a second principal surface having an opposed surface relationship with each other, the quartz crystal resonator element is mounted on the first principal surface side, the thermistor is housed in a recessed section of the second principal surface side of the package base, a plurality of electrode terminals connected to the quartz crystal resonator element or the thermistor is disposed on the second principal surface side of the package base, and a distance in a first direction perpendicular to the first principal surface from a mounting surface of the electrode terminals to the thermistor is equal to or longer than 0.05 mm.