To provide a water softening apparatus capable of executing a stable regenerating treatment by fixing the flow rate, per unit time, of recycled water fed into a water softening treatment tank.

At the time of implementing a regenerating treatment of feeding recycled water into a water softening treatment tank, an operation of feeding, into the water softening treatment tank, recycled water stored within a storage tank is executed by opening a flow-regulating valve at a specified aperture. During the execution of this operation, furthermore, a drainage time demand for the liquid level of the recycled water stored within the storage tank to reach a specified liquid level is acquired (clocking routine). Moreover, the acquired drainage time demand is compared with a standard time set in advance (time comparison routine), and the aperture of the flow-regulating valve is changed depending on the obtained comparison result.