A body surface temperature measuring device capable of appropriately measuring animal body surface temperature is realized. The body surface temperature measuring instrument (1) includes an infrared detection sensor (22) and a temperature sensing unit (2) including a cover (23) covering the infrared detection sensor, and the cover includes the animal. At least a part of the contact surface that is in close contact with the body surface and contacts the animal body surface in the cover is formed as a curved surface that swells to the animal body surface side.動物の体表温測定を適切に行うことができる体表温測定具を実現する。体表温測定具(1)は、赤外線検出センサ(22)、および、上記赤外線検出センサを覆うカバー(23)を備えている温度センシング部(2)を備えており、上記カバーは上記動物の体表面上に密着され、上記カバーにおける動物の体表に接する接触面の少なくとも一部は、上記動物の体表側に膨らんでいる曲面に形成されている。