To provide a temperature control device for heating and absorbing heat of a temperature control target by using Peltier elements and a method of preheating or precooling the temperature control device.

The temperature control device includes two sets of modules each comprising the Peltier element having a face coming into contact with the temperature control target, a heat storage body coming into contact with the other face different from the face of the Peltier element, a first temperature sensor arranged on the side of the face of the Peltier element coming into contact with the temperature control target and a second temperature sensor arranged between the Peltier element and the heat storage body and with a control means for making predetermined electric current flow in the respective Peltier elements. In the method of preheating or precooling the temperature control device, control is performed so as to make the Peltier elements of the two sets of modules come to direct contact with each other and transfer heat from one heat storage body to the other heat storage body.