PURPOSE: To freely control the temperature coefficient of pyroelectricity and attain high pyroelectricity around room temperature by binding a plurality of pyroelectric compositions for sensor devices comprised of PbZrO3 and PbTiO3 and Pb(Mg1/2W1/2)O3 in a prescribed ratio each and having PbO3 in different ratios.

CONSTITUTION: Pyroelectric thin plates 1, 2 of a pyroelectric sensor device are sandwiched between a pair of electrodes 3, 4 and an electric voltage generated between the electrodes 3, 4 is detected by a detecting circuit (D). The pyroelectric sensor device is comprised of pyroelectric compositions of 70-93mole% PbZrO3, 6-10mole% PbTiO3, and 1-20mole% Pb(Mg1/2W1/2)O3 and is formed by incorporating a plurality of the pyroelectric compositions having different ratio of Pb-(Mg1/2W1/2)O3. The temperature coefficient of pyroelectricity of the pyroelectric sensor device is thus freely controlled and especially, a high coefft. of pyroelectricity can be obtained at around room temperature.