The phase behavior of a flexible star polymer chain in good solvent near an attractive surface is investigated by multicanonical Monte Carlo simulations where the specific heat, the parallel and the perpendicular components of the gyration tensor, and the fraction of adsorbed monomers are computed. Temperature–surface attraction strength pseudo‐phase diagrams are constructed for three chain lengths (N = 31, 41, 61) with three numbers of arms (f = 3, 4, 6). The star polymer chain adopts a desorbed expanded conformation for high temperatures and low surface attraction strength. With decreasing temperature and for sufficient surface attraction strength, the star polymer chain undergoes a transition from 3D to a 2D structure. At low temperatures, the chain is mostly adsorbed for low surface attraction strength and adopts a two‐layer arrangement at high values of the latter. In this context, it is also found that the phase behavior of flexible star polymer chains in good solvent near an attractive surface is affected by the number of arms f and that a star polymer chain with a high number of arms is necessary for a precise classification of all intermediate pseudo phases.