An apparatus for additive manufacturing of three-dimensional components by successive, selective layer-by-layer exposure. Solidifying construction material layers of a construction material can be solidified by means of an energy beam in a process chamber, wherein the process chamber can be flown through or is flown through by an, especially inert, gas flow generated by a flow generation device, wherein with the gas flow and construction material particles resulting a particle mixture can be formed or is formed, wherein the particle mixture includes at least three construction material fractions differing in at least one construction material particle parameter, especially particle size and/or particle density, comprising a separation device, which is provided for separating the respective construction material particle fractions from the particle mixture by means of visual inspection, wherein the separation device comprises at least three separation sections each serving the separation of a certain construction material particle fraction.