The invention relates to a transponder system for the contactless inductive power transmission of a stationary part having at least one read coil (2) disposed on the stator (1) to a rotating part having at least one transponder coil (4) disposed on a spindle (3). The aim of the invention is to provide a transponder system of the aforementioned kind which can be used for self-sufficient sensor applications even in the vicinity of metal materials and noise fields caused by electric motors conventional in mechanical engineering. For this purpose, the surrounding (5) of the read coil (2), especially the stator is produced from a material having little magnetic permeability and good electrical conductivity, preferably aluminum. The transponder coil (4) and/or the read coil (2) are disposed as flat coil (6) on the inside and/or outside of a cylindrical periphery (9, 10) of the stator and/or rotor (11). A layer (17, 18) of a material having high magnetic permeability is provided between the flat coil (8) and the rotor (11) or stator (1), preferably in the form of a foil of an amorphous ferritic material (17) or of a non-conducting ferritic metal (18).