Electron-impact (Stark) full widths at half intensity maximum for 22 spectral lines of singly charged copper ion (Cu II) have been calculated by employing the modified semiempirical method. The calculations have been performed for an electron density of 10^17 cm^-3 and for a temperature range from 5 000 K up to 80 000 K. The obtained results, have been used to demonstrate similarities and regularities of Stark widths of Cu II spectral lines within a multiplet, a supermultiplet and a transition array. The obtained results have also been compared with the results of experiments and other theoretical data.