A steel sheet containing C: 0.0005% or more and 0.0035% or less, Si: 0.05% or less, Mn: 0.1% or more and 0.6% or less, P: 0.02% or less, S: less than 0.02%, Al: 0.01% or more and less than 0.10%, N: 0.0030% or less, B: 0.0010% or more, in which the relationship B/N≦3.0 is satisfied and the balance being Fe and inevitable impurities, and a microstructure in which the average integrated intensity f in the (111)[1-10] to (111)[-1-12] orientations on a plane parallel to a sheet surface at a position located at ¼ of the thickness of the steel sheet is 7.0 or more, in which an average ferrite grain size is 6.0 μm or more and 10.0 μm or less, and the relationships EAVE≧215 GPa, E0≧210 GPa, E45≧210 GPa, E90≧210 GPa, and −0.4≦Δr≦0.4 are satisfied.