  We investigate the pion and kaon (pi^+, K^+, K^0) electromagnetic form
factors in the space-like region: Q^2 ~< 1 GeV, based on the gauged low-energy
effective chiral action from the instanton vacuum in the large N_c limit.
Explicit flavor SU(3) symmetry breaking is taken into account. The nonlocal
contributions turn out to be crucial to reproduce the experimental data. While
the pion electromagnetic form factor is in good agreement with the data, the
kaon one seems underestimated. We also calculate the electromagnetic charge
radii for the pion and kaon: <r^2>_{pi^+}=0.455 fm^2, <r^2>_{K^+}=0.486 fm^2
and <r^2>_{K^0}=-0.055 fm^2 without any adjustable free parameter except for
the average instanton size and inter-instanton distance, and they are
compatible with the experimental data. The low-energy constant L_9 in the large
N_c limit is estimated to be 8.42*10^{-3} from the pion charge radius.
