A parton shower method for the photonic radiative correction is applied to
single W-boson production processes. The energy scale for the evolution of
the parton shower is determined so that the correct soft-photon emission is
reproduced. Photon spectra radiated from the partons are compared with tho
se from the exact matrix elements, and show a good agreement. Possible erro
rs due to an inappropriate energy-scale selection or due to the ambiguity o
f the energy-scale determination are also discussed, particularly for the m
easurements oil triple gauge couplings.