Apparatus (1, 14) for additively manufacturing of three-dimensional objects (2) by means of successive layerwise selective irradiation and consolidation of layers of a build material (3) which can be consolidated by means of an energy beam (4), wherein the energy beam (4) is guided onto a build plane (5) via an irradiation device (6), wherein an evaluation unit (11) is provided that is adapted to determine spectral information of radiation (12) emitted in the manufacturing process.