To provide a starter in which the generation of overcurrent or undue torque is prevented.

Magnet switches 81-83 for performing rated operation of a three-phase motor 21 are connected in parallel with thyristor reverse parallel connection switches SCR1-SCR3 and triggered to lengthen the conduction time gradually. Consequently, the starting current flowing through the three-phase motor 21 can be increased gradually and overcurrent can be prevented at the time of starting. When the conduction time of thyristor reverse parallel connection switches SCR1-SCR3 is lengthened gradually, the timing of trigger is quickened gradually. Alternatively, it can be triggered at a constant timing for a predetermined time at the time of quickening the timing gradually or it may be quickened stepwise.