Disclosed is a noncontact electric power transmission system having a power transmitter circuit section 10 and a power receiver circuit section 30 which are adapted to be coupled to transmit electric power from a transmitter coil Lp provided in the power transmitter circuit section 10 to a receiver coil Ls provided in the power receiver circuit section 30, in a noncontact manner by means of electromagnetic induction. The noncontact electric power transmission system comprises: a separately-excited or self-excited switching circuit 2 provided in the power transmitter circuit section 10; a control IC 3 operable to drive the switching circuit 2; an LC series resonant circuit including a capacitor Cp connected in series to the transmitter coil Lp or an LC parallel resonant circuit including a capacitor Cp connected in parallel to the transmitter coil Lp; and an LC parallel resonant circuit including a capacitor Cs connected in parallel to the receiver coil Ls, wherein an oscillating frequency (Fosc) of the control IC 3, a resonant frequency (Fpr) of the LC series resonant circuit or the LC parallel resonant circuit in the power transmitter circuit section 10, and a resonant frequency (Fsr) of the LC parallel resonant circuit in the power receiver circuit section 30, have the following relationship: Fpr