To provide a sensor and device capable of easily capturing changes and micro-changes in a temperature gradient.

The sensor is comprised of a membrane capacitor of a structure in which a membrane 12 of a ferroelectric BaTiO3 of a thickness of 30 ML (approximately 120 ) grown through the use of an MBE method is provided on a lower electrode 10 comprised of an SrTiO3 substrate doped with Nb of a thickness of 0.5 mm and in which a Pd upper electrode 14 is provided by deposition on the membrane 12. The polarization reversal of the membrane capacitor generated by the change of the temperature gradient is converted into a physical quantity i.e., a change in capacitance and measured by an LCR meter.