Abstract: An electrostatic precipitator includes charging, inertia and collection sections, which are arranged in the order mentioned along the direction of gas flow containing therein particles to be removed. The charging section includes a parallel electrode and a discharging electrode located between the parallel plates, and, thus, the particles floating in the gas passing through the charging section become charged and partly agglomerated. The inertia section includes a deflector plate arranged at a predetermined angle thereby causing the gas flow to change its course of action locally to have the particles impinge on the deflector plate due to inertia. The collection section includes a trough which is formed continuous with the deflector plate with its mouth opened against the gas flow.