Abstract: An object of the present invention is to provide a heat exchanger for a temperature control which can take a large area for transferring the heat to the fluid while it is compact, has a good efficiency for exchanging the heat, can increase and decrease the heat transferring area in conformity to the user's needs and the manufacturing cost thereof is low. The heat exchanging boards 2, 3 with a plate constitution and plural thermo modules are superposed alternately so that they have a laminate constitution. The heat exchanging board has a construction such that a flowing path defining board 5, in which a flowing path with a labyrinth construction is formed, is folded by a thin shell 7. The shell has an inflow hole into which the fluid flows and an outflow hole from which a fluid flows out passing through said flowing path with the labyrinth construction. A peltier element is used as the thermo module.