A temperature adjustment device has a first thermoelectric cooling module, a second thermoelectric cooling module on which the first thermoelectric cooling module is provided, and a heat generating element which is provided on the first thermoelectric cooling module and a temperature thereof is adjusted, where assuming that a substrate area of the first thermoelectric cooling module on which the heat generating element is provided is S1 (mm2) and that an amount of generated heat of the heat generating element is Qd (mW), the relationship of 20nullQd/S1null200 is met.