In a rotary compressor, a lower end plate cover is formed in a shape of a flat plate, and has a through hole that is provided to penetrate in the thickness direction of the lower end plate cover and that communicates with a communication groove. When a sectional area of the communication groove which passes through a center line of a rotation shaft, and is on a section along the rotation shaft direction is S1 [mm2], an area in which the through hole and the communication groove overlap each other on a plane orthogonal to the rotation shaft is S2 [mm2], and an excluding capacity of a lower cylinder chamber is V [cc], each of 0.10≤(S2/V)≤0.50, and 1.0≤(S2/S1)≤7.0 is satisfied.