This paper presents the development of an endoscopic particle image velocimetry (PIV) system adapted to high-temperature furnaces. The optical setup is designed to be able to image large fields of measurements with a collection angle of 62. This optical setup acts as a camera lens in front of the CCD camera and is set in a water-cooled jacket for its thermal protection. A strong barrel distortion is obtained when imaging a large field of view. This geometric distortion is corrected on raw particle images by specific image processing before the cross-correlation calculation. A first application of this endoscopic PIV system in a laboratory-scale furnace is presented. This shows its ability to obtain large velocity fields even in such a high-temperature confined configuration.