A method for detecting the end point of plasma etching process by using matrix comprises a step of detecting a beginning matrix including emitting intensities and/or other plasma parameters of at least two different plasma species during beginning etching process. Then, a step of detecting an etching matrix is performed in which the etching matrix includes emitting intensities and/or other plasma parameters of the at least two different plasma species at the etching reaction. An end point matrix is then computed by using the beginning as well as etching matrices and compared to a reference end point matrix to decide whether the end point is reached.