Poly-methyl methacrylate (PMMA) has been widely used as biomaterial. In order to add a new function to PMMA, we developed a method to form periodic nanostructures on PMMA surface by femtosecond laser irradiation with a wavelength of 800 nm. Since PMMA had a low absorbance of light in the near-infrared wavelength region, it was difficult to form the structures by femtosecond laser irradiation on PMMA surface. We proposed a method that the femtosecond laser was focused on a titanium (Ti) plate surface through a polymer plate. As a result, the depth of the periodic nanostructures was about 70 nm, and the period of it was about 410 nm. A cell cultivation test was carried out on PMMA plate with and without periodic nanostructures. Consequently, although cells (MG-63) on the non-irradiated PMMA plate were spread in a random direction, cell spreading on the PMMA plate with periodic nanostructures occurs along the grooves.