A sliding component comprising: a pair of sliding parts (3, 5) sliding relative to each other, suitable for use with a high-pressure gas on one side of the pair of sliding parts and a low-pressure liquid on the other side, at least one of the sliding parts having a sliding face provided with a positive pressure generation mechanism (10; 16; 18; 20) having a positive pressure generation groove (11; 17; 19; 21), provided with an annular deep groove on the high-pressure gas side, and provided with a radial deep groove connecting the annular deep groove to the low-pressure liquid side, wherein the sliding face is provided with an annular land at the peripheral edge on the high-pressure gas side thereof, the annular deep groove being isolated from the high-pressure gas side by the land, and the positive pressure generation groove (11; 17; 19; 21) is provided on the low-pressure liquid side of the annular deep groove and is connected to the low-pressure liquid side and isolated from the high-pressure gas side by the land, wherein the sliding component actively introduces the low-pressure liquid into the entire sliding face while preventing the high-pressure gas from entering the space between the sliding faces, enabling sliding with the liquid film maintained, wherein the positive pressure generation groove (11; 17; 19; 21) is one of a plurality of positive pressure generation grooves, each groove being formed by a groove constituting a Rayleigh step mechanism (10; 16; 18; 20), and at least some of the grooves each have a liquid introduction assist groove formed at a circumferentially central portion thereof. a pair of sliding parts (3, 5) sliding relative to each other, suitable for use with a high-pressure gas on one side of the pair of sliding parts and a low-pressure liquid on the other side, at least one of the sliding parts having a sliding face provided with a positive pressure generation mechanism (10; 16; 18; 20) having a positive pressure generation groove (11; 17; 19; 21), provided with an annular deep groove on the high-pressure gas side, and provided with a radial deep groove connecting the annular deep groove to the low-pressure liquid side, wherein the sliding face is provided with an annular land at the peripheral edge on the high-pressure gas side thereof, the annular deep groove being isolated from the high-pressure gas side by the land, and the positive pressure generation groove (11; 17; 19; 21) is provided on the low-pressure liquid side of the annular deep groove and is connected to the low-pressure liquid side and isolated from the high-pressure gas side by the land, wherein the sliding component actively introduces the low-pressure liquid into the entire sliding face while preventing the high-pressure gas from entering the space between the sliding faces, enabling sliding with the liquid film maintained, wherein the positive pressure generation groove (11; 17; 19; 21) is one of a plurality of positive pressure generation grooves, each groove being formed by a groove constituting a Rayleigh step mechanism (10; 16; 18; 20), and at least some of the grooves each have a liquid introduction assist groove formed at a circumferentially central portion thereof.