A hermetic compressor comprises a hermetic container, an electric motor installed inside of the hermetic container, a compressing mechanism disposed within the hermetic container and driven by the electric motor, and an oil surface detector disposed to the compressing mechanism for detecting an oil surface of lubricating oil contained inside of the hermetic container. Here, the hermetic compressor is so constructed as to maintain a constant supply of the lubricating oil to the compressing mechanism by way of controlling operation in a manner to keep a surface level of the lubricating oil stable based on a detected result of the oil surface detector.