Abstract: We have developed a LaBr₃(Ce) detector based on a customized \phi 2′′×2′′LaBr₃(Ce) crystal coupled with the Hamamatsu R13089 photomultiplier, and its key performance parameters were systematically measured. We determined the energy resolution of our detector to be 3.6% for the 662 keV γ-ray. The time resolution of our detector was found to be 270\; (22)\; ps using the cascade 1 173~1 332 keV γ-rays from ⁶⁰Co source. Furthermore, we evaluated the average activity of intrinsic radiation from our detector to be 4\,824\; (69)\; Counts/h/cm³. For comparison, the performance of the Saint-Gobain B380 and B390 detectors is also presented in this paper for reference. The excellent performance of the LaBr₃(Ce) fast timing detector in energy and time resolution has been experimentally verified, demonstrating its potential for high-precison radiation measurements and fast-timing applications.