A method for separating particles from particle-laden gas. Charged particles are formed by charging particles of a particle-laden gas. A gas jet is provided by guiding the particle-laden gas by a flow guide. Particles from the gas jet are collected to a collecting electrode by an electric field. An effective collecting area of the collecting electrode is positioned such that gas velocity gradient at each point of the effective collecting area is smaller than 10% of the maximum gas velocity in the gas jet divided by the height dimension of the jet.