The Ultra Fast Flash Observatory (UFFO) pathfinder is a payload system on-board the Russian satellite Lomonosov, scheduled to be launched in 2013. The main purpose of the UFFO pathfinder is to observe the early photons from Gamma-Ray Bursts. It consists of two instruments. The first instrument is the UFFO Burst Alert X-ray Trigger telescope (UBAT) for the fast-trigger and detection of GRB location, and the second is the Slewing Mirror Telescope (SMT) for the observation of the UV/optical afterglow from the GRB located by the UBAT. It will provide the first-ever systematic study of UV/optical emission far earlier than 1 sec after trigger. We will present the design, fabrication and the preliminary performance of the UBAT.