To improve performance, by increasing sealability of a discharge muffling chamber to improve volumetric efficiency of a rotary compressor.

The rotary compressor comprises: upper and lower cylinders 38, 40 constituting first and second rotary compression elements 32, 34; a lower support member 56 closing an opening part on a lower side of the lower cylinder 40 and having a bering 56A of a rotary shaft 16; the discharge muffling chamber 64 formed by recessing a face on a side opposed to the lower cylinder 40 of the lower support member 56 and closing the recessed part by a lower cover 68; an O-ring groove 70 formed in a face (lower face) abutted with the lower cover 68 of the bearing 56A for housing the O-ring 71; and a discharge valve 75 disposed in the discharge muffling chamber 64 of the lower support member 56 for opening/closing a discharge port 41 connecting the discharge muffling chamber 64 with the lower cylinder 40. The O-ring groove 70 is displaced in a direction opposite to the discharge valve 75 relative to a rotational shaft.