Wireless power transfer (WPT) technologies are typically inductive coupling, magnetic resonance, and electric field methods. Among them, electric field WPT has been studied to overcome the drawbacks of other approaches. The electric field WPT has many advantages, such as a simple structure, low standing power loss, reduced EMI (Electromagnetic Interference), and the ability to transfer power through metal barriers. Therefore, this paper proposes the electric field WPT system at 6.78MHz. The proposed WPT system was composed of a 6.78MHz class D inverter with a LC low pass filter, a capacitor between the transmitter and the receiver, and an impedance transformer. The system was verified using a 5.5W prototype for charging mobile devices.