To provide an improved watering apparatus according to the amount of solar radiation, by which water at an amount in accordance with the amount of solar radiation to a watering target area is supplied to the watering target area.

The watering apparatus according to the amount of solar radiation gives a charge of electric energy generated in a solar module 10 to a capacitor 58 under the control by a charge controller 36. A one-chip microcomputer 34 puts the charge controller 36 into an interrupted state when the charge amount reaches a preset charge amount set by a charge amount setting device 46, and puts a load controller 38 into a conducting state so as to drive a pump 20. Such configuration results in supplying the water of water source 22 to a watering system 24 to perform watering. The one-chip microcomputer 34 puts the load controller 38 into an interrupted state when the water supply time reaches a preset water supply time set by a water supply time setter 48, and puts the charge controller 36 into a conducting state to stop the pump 20 so as to start charge to the capacitor 58. The apparatus enables intermittent watering according to the amount of solar radiation without requiring any water tank.