A wireless power transmission system includes: a power transmitting section that converts DC energy input from a DC energy source into AC energy of a frequency f0; a transmitting antenna; and a receiving antenna. The power transmitting section includes: a class-E oscillator circuit including a switching element and a capacitor which are connected in parallel to the DC energy source, for converting the DC energy into the AC energy; and a switching control section that inputs a control signal for controlling a conduction state of the switching element to the switching element. The switching control section switches the switching element from a non-conductive state to a conductive state when a preset time period has elapsed or when a potential difference across the switching element takes a local minimum value after the switching element is switched from the conductive state to the non-conductive state.