A high strength steel sheet having a chemical composition in mass % containing: C: 0.06% or more and 0.14% or less, Si: 0.1% or more and 1.5% or less, Mn: 1.4% or more and 2.2% or less, P: 0.05% or less, S: 0.0050% or less, Al: 0.01% or more and 0.20% or less, N: 0.10% or less, Nb: 0.015% or more and 0.060% or less, and Ti: 0.001% or more and 0.030% or less, contents of S, N and Ti satisfying Formula below, optionally one of, or two or more of Cr: 0.01% or more and 0.15% or less, Mo: 0.01% or more and less than 0.10%, and V: 0.001% or more and 0.065% or less, optionally B: 0.0001% or more and less than 0.002%, optionally one of or two of Cu: 0.001% or more and 0.2% or less, and Ni: 0.001% or more and 0.1% or less, and optionally Ta, W, Sn, Sb, Ca, Mg, Zr or REM, with the content of each of these elements being 0.1% or less, a balance being Fe and an inevitable impurity, comprising, in terms of area fraction relative to an entire steel microstructure, 30% or more and 100% or less ferrite, 0% or more and 70% or less martensite, and less than 20% in total of pearlite, bainite and retained austenite, whereby the microstructure is determined according to the description, a total content of Nb and Ti contained in a precipitate having a particle size of smaller than 20 nm being 25 mass ppm or more and 220 mass ppm or less, and a difference between a maximum value and a minimum value of the total content of Nb and Ti contained in the precipitate having a particle size of smaller than 20 nm, in a longitudinal direction of the steel sheet, being smaller than 20 mass ppm, determined according to the description, % Ti − 48 / 14 % N − 48 / 32 % S ≤ 0.0000 in Formula, [%Ti] represents content (mass %) of component element Ti, [%N] represents content (mass %) of component element N, and [%S] represents content (mass %) of component element S, the yield ratio in the steel sheet being 0.70 or larger, and the difference between the maximum value and the minimum value of the yield ratio, ΔYR, in the steel sheet being 0.05 or smaller, wherein the yield ratio and the difference between the maximum value and the minimum value of the yield ratio ΔYR are determined in accordance with the specifics given in the description. C: 0.06% or more and 0.14% or less, Si: 0.1% or more and 1.5% or less, Mn: 1.4% or more and 2.2% or less, P: 0.05% or less, S: 0.0050% or less, Al: 0.01% or more and 0.20% or less, N: 0.10% or less, Nb: 0.015% or more and 0.060% or less, and Ti: 0.001% or more and 0.030% or less, contents of S, N and Ti satisfying Formula below, optionally one of, or two or more of Cr: 0.01% or more and 0.15% or less, Mo: 0.01% or more and less than 0.10%, and V: 0.001% or more and 0.065% or less, optionally B: 0.0001% or more and less than 0.002%, optionally one of or two of Cu: 0.001% or more and 0.2% or less, and Ni: 0.001% or more and 0.1% or less, and optionally Ta, W, Sn, Sb, Ca, Mg, Zr or REM, with the content of each of these elements being 0.1% or less, a balance being Fe and an inevitable impurity, comprising, in terms of area fraction relative to an entire steel microstructure, 30% or more and 100% or less ferrite, 0% or more and 70% or less martensite, and less than 20% in total of pearlite, bainite and retained austenite, whereby the microstructure is determined according to the description, a total content of Nb and Ti contained in a precipitate having a particle size of smaller than 20 nm being 25 mass ppm or more and 220 mass ppm or less, and a difference between a maximum value and a minimum value of the total content of Nb and Ti contained in the precipitate having a particle size of smaller than 20 nm, in a longitudinal direction of the steel sheet, being smaller than 20 mass ppm, determined according to the description, % Ti − 48 / 14 % N − 48 / 32 % S ≤ 0.0000 in Formula, [%Ti] represents content (mass %) of component element Ti, [%N] represents content (mass %) of component element N, and [%S] represents content (mass %) of component element S, the yield ratio in the steel sheet being 0.70 or larger, and the difference between the maximum value and the minimum value of the yield ratio, ΔYR, in the steel sheet being 0.05 or smaller, wherein the yield ratio and the difference between the maximum value and the minimum value of the yield ratio ΔYR are determined in accordance with the specifics given in the description. in Formula, [%Ti] represents content (mass %) of component element Ti, [%N] represents content (mass %) of component element N, and [%S] represents content (mass %) of component element S, the yield ratio in the steel sheet being 0.70 or larger, and the difference between the maximum value and the minimum value of the yield ratio, ΔYR, in the steel sheet being 0.05 or smaller, wherein the yield ratio and the difference between the maximum value and the minimum value of the yield ratio ΔYR are determined in accordance with the specifics given in the description.