A steel cord (10, 20) for reinforcing a rubber article, comprising a plurality of twisted strands (11, 12, 21, 22) in a multi-twisted structure, each strand (11, 12, 21, 22) comprising a plurality of twisted filaments (111, 112, 121, 122, 211, 212, 221, 222) in two or more layers, wherein the steel cord (10, 20) has a cord twist angle (α), which is an angle formed by the direction perpendicular to the longitudinal direction of the steel cord (10, 20), and the direction along the longitudinal direction of a strand (12, 22), of 78° or more and less than 84°, characterized in that: at least some of the filaments (111, 112, 121, 122, 211, 212, 221, 222) have a tensile strength of 3,000 MPa or more; and wherein the steel cord (10, 20) satisfies the following: a filament occupancy, which is a value expressed as a percentage obtained by dividing the total cross-sectional area of the filaments (111, 112, 121, 122, 211, 212, 221, 222) constituting the steel cord (10, 20) by the area of the circumcircle of the steel cord (10, 20) and multiplying the obtained value by 100, of 48% or more and less than 54%; an average crossing angle between all adjacent filaments (111, 112, 121, 122, 211, 212, 221, 222), which is an angle formed by the longitudinal direction of one filament (111, 112, 121, 122, 211, 212, 221, 222) and the longitudinal direction of another filament (111, 112, 121, 122, 211, 212, 221, 222) adjacent to the former filament (111, 112, 121, 122, 211, 212, 221, 222), other than wrapping filaments (13, 23) of less than 17°; and a gap (g) between adjacent sheath filaments (112, 122, 212, 222) constituting the strand (11, 12, 21, 22) of 0.065 mm or more. at least some of the filaments (111, 112, 121, 122, 211, 212, 221, 222) have a tensile strength of 3,000 MPa or more; and wherein the steel cord (10, 20) satisfies the following: a filament occupancy, which is a value expressed as a percentage obtained by dividing the total cross-sectional area of the filaments (111, 112, 121, 122, 211, 212, 221, 222) constituting the steel cord (10, 20) by the area of the circumcircle of the steel cord (10, 20) and multiplying the obtained value by 100, of 48% or more and less than 54%; an average crossing angle between all adjacent filaments (111, 112, 121, 122, 211, 212, 221, 222), which is an angle formed by the longitudinal direction of one filament (111, 112, 121, 122, 211, 212, 221, 222) and the longitudinal direction of another filament (111, 112, 121, 122, 211, 212, 221, 222) adjacent to the former filament (111, 112, 121, 122, 211, 212, 221, 222), other than wrapping filaments (13, 23) of less than 17°; and a gap (g) between adjacent sheath filaments (112, 122, 212, 222) constituting the strand (11, 12, 21, 22) of 0.065 mm or more. a filament occupancy, which is a value expressed as a percentage obtained by dividing the total cross-sectional area of the filaments (111, 112, 121, 122, 211, 212, 221, 222) constituting the steel cord (10, 20) by the area of the circumcircle of the steel cord (10, 20) and multiplying the obtained value by 100, of 48% or more and less than 54%; an average crossing angle between all adjacent filaments (111, 112, 121, 122, 211, 212, 221, 222), which is an angle formed by the longitudinal direction of one filament (111, 112, 121, 122, 211, 212, 221, 222) and the longitudinal direction of another filament (111, 112, 121, 122, 211, 212, 221, 222) adjacent to the former filament (111, 112, 121, 122, 211, 212, 221, 222), other than wrapping filaments (13, 23) of less than 17°; and a gap (g) between adjacent sheath filaments (112, 122, 212, 222) constituting the strand (11, 12, 21, 22) of 0.065 mm or more.