VenSpec-U is one of the three channels of the VenSpec suite onboard the ESA’s mission Envision to Venus, whose launch is foreseen in 2031. It is a UV spectrometer operating in the 190-380 nm range aiming at analyzing the sulfured gases in the high atmosphere of Venus by absorption spectroscopy and investigating the unknown “UV absorber”, thus contributing to answer one of the key questions the Envision mission will address: “How has Venus’ climate become so hostile”. VenSpec-U, developed under LATMOS (Guyancourt, France) PI-ship, is part of the spectrometer suite named ”VenSpec” led by DLR (Berlin, Germany). After presenting the Envision mission, the VenSpec suite and the scientific objectives and requirement of VenSpec-U, this manuscript provides a short overview of the current instrument design and presents the expected performances as well as the methods used to assess them.