Wet etching of NiFe and CoFe magnetic thin films was carried out using HNO₃ and HCl solutions at 25℃ to investigate etch characteristics. The etch rate of NiFe films etched with HNO₃ solution was in the range 500 ~ 1700 Å/min and the etched surface of the film was rough. CoFe films etched with HNO₃ solution had much faster etch rates than NiFe films, and the etched surface was uniform and smooth. When NiFe and CoFe films were etched with HCl solution, the etch rates were much slower (< 100 Å) than those etched with HNO₃ solution, but the etched surfaces of the films were smooth. White particles were observed, however, on the surface of etched films. From the analyses by field emission auger electron spectroscopy (FEAES) and X-ray photoelectron spectroscopy (XPS), the white particles were confirmed to be chlorine compounds containing Ni (or Co), Fe, C, and O. The submicrometer-sized patterns of NiFe and CoFe films could be defined using an etching solution containing HNO₃ and HCl.