Patterned magnetic thin films of Ni Fe Co (3 nm )/ Cu (3 nm )/ Ni Fe Co (6 nm ) spin valve structure with arrays of rectangular elements of micron and submicron sizes have been studied by ferromagnetic resonance. All the rectangular elements have the same aspect ratio of 12 but with different sizes. A set of evenly spaced peaks was observed when the magnetic field was applied near the film normal. The resonant fields of these peaks are in linear proportion with the peak number, and the separation of resonant fields between peaks are approximately inversely proportional to the width of the elements, which suggests that spin waves are excited in the film plane and along the short edge of the elements.