Sulphur dioxide (SO₂) is an important trace species in the atmosphere of Venus, especially since it may be related to a possible geological activity on the surface within the last 106 to 107 years. We used spectra from the UV spectrometer SPICAV (R ~ 200) aboard the space probe Venus Express in nadir mode: the sunlight diffused and reflected by the top of the atmosphere was analysed in a search for SO₂ spectral bands. The comparison between radiative transfer models (Monte-Carlo and SHDOM) and actual spectra confirms unambiguously the presence of SO₂, and we are able to measure both SO₂ column abundance and scale height. Horizontal variability will also be discussed, as well as possible variations with the local time (solar zenith angle).