PURPOSE: To provide an analog type differential heat, sensor for easily and quickly outputting processable data by a receiver.

CONSTITUTION: This sensor is provided with a temperature detection means for detecting ambient temperature and outputting temperature data V and a temperature ascending rate processing circuit 6 for storing the temperature data from the temperature detection means for a prescribed time T (120 seconds) and data outputting the difference amount of the past temperature data Vp before the prescribed time T (120 seconds) and the present temperature data Vn. The temperature detection means is composed of a temperature detection element 3 for detecting the ambient temperature and a temperature detection circuit 4 for converting an analog value obtained from the temperature detection element 3 to a digital value and outputting it as the temperature data V.