Abstract: A process for purifying clorosilanes from B, As, Al, P, Sb and organic impurities, comprising the following steps:(a) adsorbing at room temperature the P, As and Sb impurities by means of AlF.sub.3 and/or anhydrous MgCl.sub.2 having high specific surface and/or slight acid cationic resins, up to a maximum of 1 mg of P, As and Sb impurities per gram of AlF.sub.3 and cationic resins and up to a maximum of 800 mg of the same impurities per gram of anhydrous MgCl.sub.2 ;(b) adsorbing at room temperature the B and Al impurities by means of basic compounds according to Lewis containing nitrogen, up to a maximum of 2 mg of impurities per gram of said basic compounds;(c) adsorbing at room temperature the organic impurities by means of active coal up to a maximum of 15 mg of impurities per gram of active coal.