In this paper, we propose a ferrite-loaded inverted microstrip line (IML)-based artificial magnetic conductor (AMC) with a novel design that can provide complete magnetic shielding at the backside of the transmitting (Tx) coil while slightly improving the power transfer efficiency (PTE) of a wireless power transfer system (WPTS). The target frequency of the WPTS application is approximately 6.78 MHz. In the proposed design, the AMC is placed behind the Tx coil, and its magnetic shielding capability and PTE performance were verified through simulations and measurements. The size of the proposed AMC is 528 × 528 × 6.6 mm³. The measurement results verified that, compared with the Tx coil without an AMC surface, the proposed ferrite-loaded IML-based AMC can provide complete magnetic shielding while improving the PTE of the WPTS by approximately 8.05%.