PURPOSE: To enhance workability during assembly of an infrared sensor device and to increase the yield of the device by eliminating the need for connections made by lead wire.

CONSTITUTION: An infrared array sensor 1, in which the electrodes of a pyroelectric element to be connected to the external are aligned on the light receiving surface of a pyroelectric base and installed in proximity to one another, and a circuit substrate 2 having windows 9 bored therethrough to correspond to the pyroelectric element and having the grating 10 of the windows and/or a wiring pattern formed on its peripheral side opposite the light-receiving side, are used. The infrared array sensor 1 is bonded to that side of the circuit substrate 2 which is opposite the light-receiving side, so that infrared rays pass through the windows 9 and impinge on the pyroelectric element, and also that the electrodes are connected to the wiring pattern.