The etch characteristics of magnetic tunnel junction (MTJ) stack patterned with nanometer size using e-beam lithography process was investigated in an inductively coupled plasma reactive ion etching using HBr/Ar and Cl2/Ar palsma. The etch profiles of MTJ stack were examined for the variation of gas concentration in HBr/Ar and Cl2/Ar gas mix. The etch profiles of etched MTJ stack were observed by field emission scanning electron microscope. The best etch profile of etched MTJ stack was obtained at 10% Cl2/Ar or 20% HBr/Ar gas concentration.