Abstract: This multi channel temperature controller includes several temperature sensors, an electronic multiplexer which receives output signals from these temperature sensors and which sequentially supplies these signals to its output according to the switching action of a selection signal, and an amplifier which receives the output of the electronic multiplexer. Thereby, noise such as due to thermal electro motive force generated in the contacts of prior art sets of reed relays for switching over such temperature sensor output signals can be eliminated. Further, optionally, there may be provided several input circuits, one interposed between each of these temperature sensors and the electronic multiplexer, and each including a capacitor which has electrostatic capacitance substantially greater than the electrostatic capacitance existing between its input circuit and the corresponding temperature sensor. Thereby, common mode voltage noises are eliminated or minimized.