In this paper we present the current status of the development and test of a 10 micrometers single-mode fiber. We explain why this component is useful to mid-infrared interferometry and how critical it can be. Two applications are addressed: imaging interferometry and nulling at 10 micrometers . We given an outlook of what can be expected from this technology for interferometry when more components are available.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.