Christian Ferrari and Hynek Kovarik Resonances Width in Crossed Electric and Magnetic Fields (427K, Postscript) ABSTRACT. We study the spectral properties of a charged particle confined to a two-dimensional plane and submitted to homogeneous magnetic and electric fields and an impurity potential. We use the method of complex translations to prove that the life-times of resonances induced by the presence of electric field are at least Gaussian long as the electric field tends to zero.