Abstract: A hermetic compressor (100) includes an electric element (110), a compression element (112), and a hermetic container (102). The compression element includes a shaft (118), a cylinder block (124), a piston (136), a connection section (144), and an oil supply mechanism (130). The piston has a columnar seal section (160) in sliding contact with an inner peripheral face of the cylinder, two extension sections (162) that have circular arc faces each having the same radius as a radius of the seal section and extend from the seal section to the bottom dead center side in the axial direction with a circumferential gap therebetween, and a columnar capture section (164) that extends further toward the bottom dead center side than the extension section and has a smaller radius than the radius of the seal section.