PURPOSE: To connect the electrodes of infrared array sensor devices to the electrodes on a circuit board electrically without a defective connection and, further, without a short-circuit between the adjacent electrodes.

CONSTITUTION: A plurality of second electrodes 12 are provided on the rear of a pyroelectric board 7 and the respective electrodes 12 are covered with blackened films 9. A plurality of first electrodes 2 are provided on the surface of the board 7 at the positions corresponding to the electrodes 12. After conductive paste 5 is applied to the respective electrode 2, the board 7 is turned upside down and a circuit board 3 is so provided beneath the board 7 as to make the electrodes 2 of the board 7 and the electrodes 4 of the board 3 face each other with spacers 6 therebetween. The conductive paste 5 hangs downward onto the electrodes 4 below and is solidified into hand-drum shapes in a furnace to connect the electrodes 2 to the electrodes 4 electrically. The electrical connection can be achieved regardless of the coating shapes of the conductive paste 5 and the unevenness of the board 7.