Removal of rubber contaminants from chrome-plated die with slots was studied using an acousto-optic Q-switched Nd:YAG nanosecond pulsed laser with an average power of 100 W. The contaminants deposited non-uniformly on the die can be distinguished as rubber particles with a nominal diameter of 10 μm, located mainly in the plane region (PR), while a thick rubber layer up to 50 μm can be discovered in the slot region (SR). Results show that, by positive defocusing the laser with single pulse energy density of 0.97 J/cm2 and adding the argon gas, single-scan high-efficiency cleaning of the slots could be achieved, and the net cracks on the chromium layer could be cleaned too. The optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM) were used to investigate the surface of the die before and after cleaning.