PROBLEM TO BE SOLVED: To provide a water power generator capable of adjusting a direction in which a water flow abuts on the vane of a turbine (water turbine), and capable of efficiently converting a small amount of water power to electric energy.SOLUTION: A water power generator includes a turbine having a rotational shaft in a direction orthogonal to a water flow, and a water level adjustment gate positioned on the front side of the turbine and configured to adjust a water level. The water level adjustment gate can rotate or move up and down, and has a flowing water curved surface part for guiding water in a lowering direction toward a turbine vane of the turbine.SELECTED DRAWING: Figure 1