The method of operating desalination treatment apparatus and desalting device

Reliably prevent the deposition of scale electrostatic desalting processing apparatus. Desalination treatment apparatus of the present invention (1) comprises an electrostatic desalting unit (10, 60), from the previous step of desalting regeneration step, desalting unit and held water volume (4) and the feed water flow rate the scale inhibitor was introduced in the derived time period in the supply water to stop the introduction of scale inhibitor after a predetermined time has elapsed or after a predetermined ion concentration arrival. Desalination treatment apparatus of the present invention (1), the scale inhibitor was supplied to the supplying water to the time of stopping the electrostatic desalting unit (10), introduction of scale inhibitor after a predetermined time has elapsed or after a predetermined ion concentration arrival a stop. Alternatively, feed in stopping the electrostatic desalting unit (30, 60), the low ionic concentration water of an amount based on the held water volume of the desalting unit (4) to the electrostatic desalting unit (30, 60) to.