Infared sensor

An infrared sensor comprising:

• an infrared sensor chip in which a plurality of pixel portions is disposed in an array on one surface side of a semiconductor substrate, each of said pixel portions including a temperature-sensitive portion formed of a thermopile;
• an IC chip configured to process an output signal of said infrared sensor chip;
• and
• a package in which said infrared sensor chip and said IC chip are accommodated,
• wherein said package includes:
• a package main body on which said infrared sensor chip and said IC chip are mounted to be arranged side-by-side;
• and a package cover which is hermetically bonded to said package main body so as to surround said infrared sensor chip and said IC chip together with said package main body, said package cover having a function of transmitting infrared rays to be detected by said infrared sensor chip, and
• said package is provided therein with a cover member which includes a window hole through which infrared rays pass into said infrared sensor chip, said cover member equalizing, among the pixel portions, the amounts of temperature change of hot junctions and cold junctions caused by heating of said IC chip.