An access control system with at least one entrance lane (4) has two or more antenna coils (12 to 15) arranged in pairs mutually opposing each other. Each antenna coil pair (12, 13 or 14, 15) is actuated by a reading device (20) for reading out a transponder (22) carried by the user, the transponder (22) having a transponder coil (24) coupleable with the antenna coils (12 to 15). The two mutually opposing antenna coils (12, 13 or 14, 15) of a pair are actuated at the same time, but alternately either in an in-phase or antiphase operation mode. For reading out the transponder (22) carried by the user the one operation mode, with which the transponder (22) is detected, is maintained until the reading transaction is completed.