In superconducting radiofrequency accelerating cavities for particle accelerators, the Nb/Cu structure is one of the alternatives to bulk Nb but R&D is required to achieve a reproducible performance that competes with bulk Nb. The DC entry field Hen and critical temperature were studied in the thin Nb films deposited by magnetron sputtering on Cu substrate. The Nb surfaces were further treated by Nd:YAG laser at four energy doses (D1 = 350, D2 = 233, D3 = 175 and D4 = 140 J cm-2). The superconducting properties and other characteristics obtained by atomic force microscope, scanning electron microscope and x-ray diffraction were compared before and after laser treatment. The laser treatment increased the field of first flux entry by up to 65% compared to a non-irradiated sample. The laser irradiation also led to reduction of surface roughness, improvement of the surface morphology, reduction in crystallite size and increase of lattice parameter.