A wireless power transmission unit includes an oscillator for converting DC energy into RF energy having a frequency f0 and a first antenna for transmitting the RF energy. The first antenna includes a first inductor and a first capacitor that are connected together in series to form a series resonant circuit with a resonant frequency fT. The unit further includes a second antenna for receiving, by resonant magnetic coupling, at least a part of the RF energy that has been transmitted by the first antenna. The second antenna includes a second inductor and a second capacitor that are connected in parallel with each other to form a parallel resonant circuit with a resonant frequency fR. The resonant frequencies fT and fR are set to be substantially equal to the frequency f0 of the RF energy, the oscillator has a voltage step-up ratio Voc, the first inductor has an inductance L1, the second inductor has an inductance L2, the second inductor is coupled with the first inductor by a resonant magnetic field at a coupling coefficient k which is set to be less than 0.5, and the power transmission unit satisfies (L2/L1)≧4(k/Voc)2.