An example wireless power transmitter may include a transistor configured to output an amplified signal, a first capacitor coupled to the transistor in parallel, a first LC resonant circuit coupled to the transistor in parallel, a third capacitor having a first end coupled to an output terminal of the transistor and the first LC resonant circuit, a feeding coil coupled to a second end of the third capacitor in series, and having at least a part configured to form a second LC resonant circuit with the third capacitor, and a transmission resonator including a transmission coil and a fourth capacitor coupled to the transmission coil in series. At least a part of the transmission coil may be magnetically coupled with the feeding coil, and at least a part of power received from the feeding coil may be output to an outside through the transmission resonator.