A non-contact electric power transmitting device configured to transmit an electric power to an electric power receiving device in a non-contact manner, the non-contact electric power transmitting device comprising: an electric power transmitting unit configured to transmit the electric power to the electric power receiving device; an inverter configured to supply the electric power to be transmitted to the electric power receiving device corresponding to a drive frequency to the electric power transmitting unit, the inverter being a voltage inverter; and an electronic control unit configured to control the inverter, wherein the electronic control unit is configured to perform: i) first control for controlling the electric power to be transmitted to a target electric power by adjusting a duty of an output voltage of the inverter, characterized in that the electronic control unit is further configured to perform: ii) second control for controlling a turn-on current, representing an output current of the inverter at a time when the output voltage rises, by adjusting the drive frequency, and iii) adjusting the duty and the drive frequency such that a current supplied from the inverter to the electric power transmitting unit decreases within a range in which the turn-on current is equal to or smaller than a limit value, while controlling the electric power to be transmitted to the target electric power in the first control; and the electronic control unit is configured, in a case where there are two drive frequencies at which the turn-on current is a predetermined value equal to or smaller than the limit value under a condition that the electric power to be transmitted is constant, to set that one of the two drive frequencies, at which a magnitude of the current supplied from the inverter to the electric power transmitting unit is the smaller, as an initial adjusted value of the drive frequency in the second control, in executing a process of activating the inverter. an electric power transmitting unit configured to transmit the electric power to the electric power receiving device; an inverter configured to supply the electric power to be transmitted to the electric power receiving device corresponding to a drive frequency to the electric power transmitting unit, the inverter being a voltage inverter; and an electronic control unit configured to control the inverter, wherein the electronic control unit is configured to perform: i) first control for controlling the electric power to be transmitted to a target electric power by adjusting a duty of an output voltage of the inverter, i) first control for controlling the electric power to be transmitted to a target electric power by adjusting a duty of an output voltage of the inverter, ii) second control for controlling a turn-on current, representing an output current of the inverter at a time when the output voltage rises, by adjusting the drive frequency, and iii) adjusting the duty and the drive frequency such that a current supplied from the inverter to the electric power transmitting unit decreases within a range in which the turn-on current is equal to or smaller than a limit value, while controlling the electric power to be transmitted to the target electric power in the first control; and