The magnetization reversal phenomenon in a submicron magnetic wire with a trilayer structure consisting of NiFe(20nm)/Cu(10nm)/NiFe(5nm) was investigated by measuring the electric resistance in an external magnetic field. A giant magnetoresistance (GMR) effect of about 0.8 % was observed when the magnetizations in two NiFe layers are oriented antiparallel. It is demonstrated that magnetization reversal phenomena can be very sensitively investigated by utilizing the GMR effect
