M u lt il ay er Stru ctu re s w it h G ia nt Ma gn et ore sis tan ce F. St obi ec k i a and T. St o bie ck i b ; Ê a I n st i t ut e of Mo l ecul ar P hysi cs, Po l i sh Aca demy of Sciences Sm ol uchows kiego 17, 60-179 Po zna¥, Po l and b D epa rtm ent of El ectro ni cs, Uni versi ty of Mi ni ng and Meta l l urg y Al. Mi cki ewicza 30, 30-059 Kra k §w, Po l and T h e phe nomeno logi cal de scrip tio n of the giant magnetoresistance e˜ect as w ell as the discussion of the re quirements w hich must be fulÙlled in giant magnetoresistance thin Ùlm structures are given in the Ùrst part of our review. In the second part the magneti zation reversal and giant magnetoresistance e˜ect of antif erromagnetical l y coupled multilayers , spin v alve and pseudo-spin v alve thin Ùlm structures are explained. For these structures w e also discuss the inÛuence of the structure def ects such as surf ace roughness and pinholes on the giant magnetoresistance e˜ect.