In a water treatment apparatus, a tilted plate is disposed at an incline relative to a horizontal plane. Water to be treated is passed over the upper surface of the tilted plate. A discharge forming body is disposed across a gas layer above a water film formed by the water to be treated flowing over the tilted plate. A droplet forming apparatus exerts power on the water film so that at least some of the water to be treated shoots upward in the form of droplets.