A camshaft adjuster (1) is provided for an internal combustion engine of the vane cell type, having a stator (2) and a rotor (3) which can be rotated relative to the stator (2) and consists of a plurality of rotor parts (4, 5, 6) which are connected to one another, wherein the rotor (3) can be connected fixedly to a camshaft (7) of the internal combustion engine so as to rotate with it, and a first rotor part (4) is configured in such a way that the camshaft (7) is supported with contact on the first rotor part (4) in an operating state, wherein the first rotor part (4) is produced by a sintering process, and at least one first supporting surface (9), supporting the camshaft (7), of the first rotor part (4) is set geometrically by a chipless machining operation, and to a method for producing a rotor (3) for a camshaft adjuster (1) of this type.