NOVELTY - The apparatus has a spiral track i.e. spiral rail (21), pivotally supported on an axis line along horizontal direction in a center part along length direction. A mobile body is moved to a lower end part side of the spiral track, while guiding the mobile body to the spiral track and rotating the mobile body from an upper end part side of the spiral track. A rotating shaft (26) is rotated by rotation of the mobile body when the spiral track fluctuates and the spiral track is reached to a setting angle such that rotational energy is generated in the rotating shaft from a generator (56).    USE - Seesaw-type electric power generating apparatus e.g. sunlight/wind force/wave power utilization type electric power generating apparatus, for use in a building i.e. Japan house, and for a water power generation system, a thermal power generation system, a nuclear power generation system, a wind power generation system, a photovoltaic power generation system, a geothermal energy generation system, a wave-powered electricity generation system and a tidal current generation system.    ADVANTAGE - The rotating shaft is rotated by rotation of the mobile body when the spiral track fluctuates and the spiral track is reached to the setting angle such that the rotational energy can be generated in the rotating shaft from the generator, so that supply of external energy is not required, thus improving economical efficiency and safety of the apparatus and freedom degree of an installation place and avoiding bad influence to an environment, and hence existing extremely outstanding effect for installing thing that does not require big scale like evacuation areas such as emergency in the installation place when installation requirements are comparatively severe.    DETAILED DESCRIPTION - The rotational energy is electric power generation energy.    DESCRIPTION OF DRAWING(S) - The drawing shows a front view of an electric power generating apparatus.    Spiral rail (21)    Rotating shaft (26)    Output side rotating shaft (53)    Clutch (54)    Generator (56)