Excellent strain aging hardening type steel sheet and a manufacturing method thereof aging resistance after baking finish

To achieve both natural non-aging property and bake hardenability, provides superior strain aging hardening type steel sheet aging resistance after baking finish. By mass%, C: 0.0010~0.010%, Si: 0.005~1.0%, Mn: 0.08~1.0%, P: 0.003~0.10%, S: 0.0005~0.020%, Al: 0.010~0.10%, Cr: 0.005~0.20%, Mo: 0.005~0.20%, Ti: 0.002~0. 10%, Nb: 0.002~0.10%, N: containing 0.001 to 0.005%, the balance being Fe and unavoidable impurities, the ferrite fraction is 98% or more, ferrite an average particle size of 5 to 30 [mu] m, a minimum value of the dislocation density in the 1/2 thickness portion and the surface layer portion of the sheet thickness is at 5 ×