Power generator

A power generator comprising:

• an electret including a first charged surface and a second charged surface, the first and second charged surfaces having opposite polarities,
• a first electrode partially formed on the first charged surface such that the first charged surface has a portion as a current collecting surface that is exposed outward,
• a second electrode formed on the second charged surface,
• a third electrode disposed to face the first charged surface with a space, the third electrode being configured to move relative to, and in parallel to, the first charged surface, and
• at least one of a power storage unit or an output unit, wherein
• the first electrode and the second electrode form a first power generating unit,
• the third electrode and the second electrode form a second power generating unit,
• at least one of the power storage unit or the output unit is electrically connected to both the first power generating unit and the second power generating unit, and
• the electret is formed by polarizing an electret material that includes an inorganic dielectric having a bandgap energy of 4 eV or more.