A thin steel sheet having a thickness of 0.4 mm to 2.6 mm, a tensile strength of 980 MPa or more and a fatigue strength ratio of 0.65 or more, further comprising: a component composition containing C: 0.10% to 0.35%, Si: 0.01% to 2.0%, Mn: 0.8% to 2.35%, P: 0.05% or less, S: 0.005% or less, Al: 0.005% to 0.10%, N: 0.0060% or less, and optionally one or two or more of V: 0.001% to 1%, Ti: 0.001% to 0.3%, Nb: 0.001% to 0.3%, Cr: 0.001% to 1.0%, Mo: 0.001% to 1.0%, Ni: 0.01% to 1.0%, Cu: 0.01% to 1.0%, B: 0.0002% to 0.0050%, Sb: 0.001% to 0.050%, a REM: 0.0002% to 0.050%, Mg: 0.0002% to 0.050%, and Ca: 0.0002% to 0.050% on a mass basis, the balance being Fe and inevitable impurities; and a steel structure which has a ferrite area fraction of 30% or less (including 0%), a bainite area fraction of 5% or less (including 0%), a martensite and tempered martensite area fraction of 70% or more (including 100%), and a retained austenite area fraction of 2.0% or less (including 0%) and in which the ratio of the dislocation density in the range of 0 μ m to 20 μ m from a surface of the steel sheet to the dislocation density of a through-thickness central portion of the steel sheet is 90% to 110% and the average of the top 10% of the sizes of cementite grains located in a depth of up to 100 μ m from a surface of the steel sheet is 300 nm or less, wherein a maximum camber of the steel sheet sheared to a length of 1 m in a longitudinal direction of the steel sheet is 15 mm or less, wherein R max - R ave is 0.8 mm or less, wherein the maximum of the minimum bend radii, R max, the average of the minimum bend radii, R ave, as well as the tensile strength, the fatigue strength ratio, the ferrite area fraction, the bainite area fraction, the martensite and tempered martensite area fraction, the retained austenite area fraction, the ratio of the dislocation density in the range of 0 μ m to 20 μ m from a surface of the steel sheet to the dislocation density of a through-thickness central portion of the steel sheet, the average of the top 10% of the sizes of cementite grains located in a depth of up to 100 μ m from a surface of the steel sheet and the maximum camber of the steel sheet sheared to a length of 1 m in a longitudinal direction of the steel sheet are determined in accordance with the specifics given in the description. a component composition containing C: 0.10% to 0.35%, Si: 0.01% to 2.0%, Mn: 0.8% to 2.35%, P: 0.05% or less, S: 0.005% or less, Al: 0.005% to 0.10%, N: 0.0060% or less, and optionally one or two or more of V: 0.001% to 1%, Ti: 0.001% to 0.3%, Nb: 0.001% to 0.3%, Cr: 0.001% to 1.0%, Mo: 0.001% to 1.0%, Ni: 0.01% to 1.0%, Cu: 0.01% to 1.0%, B: 0.0002% to 0.0050%, Sb: 0.001% to 0.050%, a REM: 0.0002% to 0.050%, Mg: 0.0002% to 0.050%, and Ca: 0.0002% to 0.050% on a mass basis, the balance being Fe and inevitable impurities; and C: 0.10% to 0.35%, Si: 0.01% to 2.0%, Mn: 0.8% to 2.35%, P: 0.05% or less, S: 0.005% or less, Al: 0.005% to 0.10%, N: 0.0060% or less, and optionally one or two or more of V: 0.001% to 1%, Ti: 0.001% to 0.3%, Nb: 0.001% to 0.3%, Cr: 0.001% to 1.0%, Mo: 0.001% to 1.0%, Ni: 0.01% to 1.0%, Cu: 0.01% to 1.0%, B: 0.0002% to 0.0050%, Sb: 0.001% to 0.050%, a REM: 0.0002% to 0.050%, Mg: 0.0002% to 0.050%, and Ca: 0.0002% to 0.050% on a mass basis, the balance being Fe and inevitable impurities; and a steel structure which has a ferrite area fraction of 30% or less (including 0%), a bainite area fraction of 5% or less (including 0%), a martensite and tempered martensite area fraction of 70% or more (including 100%), and a retained austenite area fraction of 2.0% or less (including 0%) and in which the ratio of the dislocation density in the range of 0 μ m to 20 μ m from a surface of the steel sheet to the dislocation density of a through-thickness central portion of the steel sheet is 90% to 110% and the average of the top 10% of the sizes of cementite grains located in a depth of up to 100 μ m from a surface of the steel sheet is 300 nm or less, wherein a maximum camber of the steel sheet sheared to a length of 1 m in a longitudinal direction of the steel sheet is 15 mm or less, wherein R max - R ave is 0.8 mm or less, wherein the maximum of the minimum bend radii, R max, the average of the minimum bend radii, R ave, as well as the tensile strength, the fatigue strength ratio, the ferrite area fraction, the bainite area fraction, the martensite and tempered martensite area fraction, the retained austenite area fraction, the ratio of the dislocation density in the range of 0 μ m to 20 μ m from a surface of the steel sheet to the dislocation density of a through-thickness central portion of the steel sheet, the average of the top 10% of the sizes of cementite grains located in a depth of up to 100 μ m from a surface of the steel sheet and the maximum camber of the steel sheet sheared to a length of 1 m in a longitudinal direction of the steel sheet are determined in accordance with the specifics given in the description.