To provide a submerged generator having high power generation energy efficiency.

The submerged generator rotating an existing generator built inside a strut with sealed and waterproofed under water, and generating power by power of a vertical shaft rotation opening/closing mesh type hydraulic turbine installed on a river bottom or sea bottom and rotated by water current, is constructed. Characteristics of the hydraulic turbine are: it is not required to orient angle thereof to a direction of water current; and it has a cycle that a movable blade is pushed by water current at an upstream side and a mesh arm closes so that rotary force is obtained, opens at a downstream side after a half rotation to turn water current aside, goes up to the upstream side with the mesh open, and closes at the most upstream side. Since the hydraulic turbine rotate under water, noise is not generated. Scenery is not destroyed and carbon dioxide is not emitted at all. Ancillary work of a conduit and dam, a difference in height of water current or the like is not required, and power can be generated by only drilling a hole in a rock bed of the river bottom and the sea bottom and installing the strut. Since the generator can be installed at any place if water current and water depth is sufficient, and does not pollute water itself, the generator can be installed anywhere in the world.