The invention provides a power transmitting system, whereby frequency can be easily and accurately determined at the time of transmitting power, and energy transmission efficiency is improved. This power transmitting system is characterized in having: a power transmitting antenna unit (108) having an alternating current voltage inputted thereto; a current detecting unit (107), which detects a current flowing in the power transmitting antenna unit; a peak hold unit (120), which acquires a peak value of a current detected by means of the current detecting unit; a timer unit (110), which measures a timer value, i.e., a difference between a time when the switching element is turned on, and a time when zero current is detected by means of the current detecting unit; a frequency determining unit (110), which determines the frequency on the basis of the peak value obtained by means of the peak hold unit, and the timer value measured by means of the timer unit; and a control unit (110) which transmits power on the basis of the frequency determined by means of the frequency determining unit.