High-speed UV-laser drill system has been developed for package substrate processing as a new generation program of the laser system division. As a laser source, diode-pumped all-solid-state laser with third harmonic crystal has been applied. A high-speed-switching electroptic instrument is placed along the output laser beam axis in order to switch the polarization quickly, which enables the polarization beam splitter to divide the laser beam to the different axis alternatively for the efficient processing. As a result, the throughput reached up to 1000 holes/second for the drilled hole diameter of 50μm with the pitch of 0.5mm on the substrate. At the same time, the standard deviation of the hole diameter was reduced to ±2μm(3σ) and the roundness was within 5％ (3σ) by optimizing the beam transfer optics system. The hole position deviation on the substrate was decreased within 10μm by the temperature control system in the scanning mirror box.