Fluorescence spectra and rise as well as decay curves of 1‐ethylpyrene (EPy) in poly(methyl methacrylate) films changed using a XeCl (308‐nm) excimer laser as an ablation source. This phenomenon was observed not only for the ablated area but also for the masked region of about 20 &mgr;m around the ablated area and was attributed to the change of the dispersion condition of EPy. Effects of laser ablation upon properties of polymer films were elucidated by analyzing fluorescence dynamics using a microscope and under a total internal reflection condition.