A hermetic compressor according to the present invention includes: an electric element (103); a compression element (105) driven by the electric element (103); and a sealed container (101) accommodating the electric element (103) and the compression element (105), the sealed container (101) storing an oil (113). The compression element (105) includes: a crank shaft (119) including a main shaft (129), an eccentric shaft (127), and an oil supply mechanism (131); a cylinder block (121) including a main bearing (137) and a cylinder (135), the main bearing (137) pivotally supporting the main shaft (129) of the crank shaft (119), the cylinder (135) forming a compression chamber (133); a piston (123) configured to move inside the cylinder (135) in a reciprocating manner; and a connector (125) connecting the eccentric shaft (127) and the piston (123). A first oil groove (139A) extending in a circumferential direction of the cylinder (135) is provided on at least part of an upper outer peripheral surface of the cylinder (135).