Abstract: A threshold temperature detection is made by measuring the reverse saturation current of a transistor subjected to the temperature to be measured. It is shown that, for temperatures close to the ambient temperature, the sensitivity of this detector is very high. Furthermore, in making a circuit that measures the relative variations of the reverse saturation current, a temperature detector is made which is independent of variations in characteristics resulting from manufacturng tolerances for integrated circuits. This circuit is particularly designed to be implanted in the same substrate as a memory circuit of the type with memory cells, provided with floating gate transistors.