An infrared temperature sensor including: a sensor case made of metal and including a first airspace (a light guiding region) that guides infrared rays entering from an infrared entrance window, and a second airspace (a light shielding region) that is adjacent to the light guiding region via a partition wall, and where an upper wall that blocks entrance of the infrared rays is formed on an entrance side of the infrared rays; a film that absorbs the infrared rays reaching the film through the light guiding region, and converts the infrared rays to heat; a sensor cover that is made of metal and arranged opposing the sensor case via the film; an infrared detection element and a temperature compensation element arranged on the film, wherein the light guiding region and the light shielding region have substantially symmetrical forms with respect to the partition wall.