A timepiece comprises an atomic oscillator for generating and outputting a reference clock signal, and a timepiece module that operates based on the reference clock signal, wherein the atomic oscillator and the timepiece module are disposed separately so as to be thermally separated. The timepiece also comprises a crystal oscillator for generating and outputting a first oscillation signal, an atomic oscillator for generating and outputting a second oscillation signal with a higher precision than the first oscillation signal, a timepiece module that operates based on the first oscillation signal and the second oscillation signal, and a thermal separator for thermally separating the atomic oscillator from the crystal oscillator and the timepiece module. A portable timepiece and electronic device can thereby be configured so that the effects of heat generation can be reduced and power consumption can be reduced even in cases in which the atomic oscillator is used as a reference oscillator.