To provide a starting apparatus of a poly phase induction motor for also contributing to energy saving by achieving a reduced voltage starting by a relative simple circuit configuration.

While a reduced voltage starting period passes after inputting the starting voltage of a three-phase motor IM, a relay section 24 of voltage control sections 20a and 20b is controlled to a break state by a timer control unit 30, and a reduced voltage Von/off is supplied to the three-phase motor IM by a triac section 22 of the voltage control units 20a and 20b. After the reduced voltage starting period is passed, the relay section 24 is controlled to a conduction state by a timer control unit 30, thus preventing the reduced voltage Von/off by the triac section 22 from being supplied and supplying a voltage by the three-phase AC power supply to the three-phase motor IM, as it is.