PURPOSE: To make cooling components and heat components around an image pickup element small in size for constant temperature processing for the image pickup element.

CONSTITUTION: An image pickup device is provided with a detector 4 detecting a temperature of an image pickup element 1 and a means 6 to generate a control signal based on the detection, and a Peltier element 2 driven by a constant current circuit able to supply a positive or a negative current proportional to the control signal is coupled thermally between the image pickup element and a heat sink 3. When the temperature of the image pickup element is higher than a range of a prescribed temperature, the Peltier element is driven by a positive constant current I1 proportional to the temperature to cool the image pickup element. When the temperature of the image pickup element is lower than a range of a prescribed temperature, the Peltier element is driven by a negative constant current proportional to the temperature decrease whose rate of change with respect to the temperature is less than the case when the temperature of the image pickup element is higher than a range of a prescribed temperature to heat the image pickup element. When the temperature of the image pickup element stays within the range of the prescribed temperature, no current flows to the Peltier element to set the temperature of the image pickup element within the range of the prescribed temperature.