PURPOSE: To obtain a sharp heat image by fundamentally solving the blur of the heat image and preventing the lowering in sensitivity, by unidimensionally or two- dimensionally arranging a plurality of piezoelectric elements in a mutually separated state and setting the electrode provided to one surface of each piezoelectric element to a common electrode.

CONSTITUTION: A plurality of piezoelectric elements 1 are unidimensionally or two- dimensionally arranged in a mutually separated state. A connection electrode 2 is provided to one surface of each piezoelectric element 1 and the infrared ray receiving electrode 3 provided so as to straddle the remaining other surface of the piezoelectric elements 1 is used as a common electrode also being an earth electrode. By this constitution, there is no direct giving and receiving of heat between the elements, and the mutual heat dissipation exchange and the heat conduction through the common electrode and a semiconductive element is small by one figure or more as compared with the expanse of the heat in a piezoelectric material by heat conduction. Therefore, the same result as such a case that the piezoelectric elements are mutually independent is obtained and the heat blur (crosstalk) of each piezoelectric element is prevented to eliminate the lowering in sensitivity and a sharp heat distribution image can be obtained.