Abstract: A hermetic compressor includes a cylindrical hole (117) forming a compression space (115) and having a tapered portion (127) so as to increase its inner diameter from the top dead center to the bottom dead center of a piston (123). The piston (123) is reversed in its inclination direction with respect to the axial center of the cylindrical hole (117) in the initial stage of the compression stroke. This reduces the contact between the piston (123) and the cylindrical hole (117) at the time of the reversal, as compared with the case in which the piston (123) is reversed in its inclination direction in the middle or later stage of the compression stroke. As a result, the hermetic compressor is reliable and has low noise level.