Infrared detection apparatus

An infrared detection apparatus for attachment to a housing installed in a space on an installation surface of the space, the installation surface being substantially perpendicular to a bottom surface of the space and being at a predetermined height from the bottom surface, the infrared detection apparatus comprising:

• a lens that allows infrared light to pass therethrough;
• and
• an infrared sensor that includes infrared detection elements arranged in two or more columns, the infrared sensor being rotated around a scan rotation axis that passes through part of the lens to scan a detection range and outputting an output signal indicating a thermal image of the detection range,
• wherein an arrangement surface, on which the infrared detection elements are arranged in the two or more columns, is inclined at a first angle with respect to the installation surface,
• wherein the lens is disposed at a position displaced from the infrared sensor so that an angle defined by a line connecting a center of the infrared detection elements arranged in the two or more columns and an optical center of the lens and a line perpendicular to the arrangement surface is a second angle, and
• wherein the infrared detection apparatus has a field of view having a center that is lower than a direction perpendicular to the installation surface by an amount corresponding to a third angle that is a sum of the first angle and the second angle.