A tool and a process for removing particles from a reticle are described. The tool is disposed in front of a pellicle particle detector, including at least a gas spray member toward a surface of the reticle for removing particles and a supporting member supporting the gas spray member in front of the pellicle particle detector. The supporting member can further fix the tool onto the pellicle particle detector. In the particle removing process, when particles are detected on the reticle, the tool is turned on and the reticle is loaded into the pellicle particle detector through the gas spray member in order to remove the particles from the reticle before the pellicle particle detector detects the particles.