The temperature control system is provided with a lower heat removing unit which is disposed at the bottom of a reactor inside which an exothermic reaction takes place and through which a liquid coolant is flowed, and an upper heat removing unit which is disposed in the reactor further above from the lower heat removing unit and through which the liquid coolant is flowed, recovering reaction heat inside the reactor and controlling a temperature inside the reactor. The lower heat removing unit is supplied with the liquid coolant which is adjusted for temperature by a first temperature adjustment unit, and the upper heat removing unit is supplied with the liquid coolant which is adjusted for temperature by a second temperature adjustment unit different from the first temperature adjustment unit.