  We examine the uncertainty of the calculation of the atmospheric neutrino
flux and present a way to reduce it using accurately measured atmospheric muon
flux. Considering the difference of the hadronic interaction model and the real
one as a variation of hadronic interaction, we find a quantitative estimation
method for the error of the atmospheric neutrino flux calculation from the
residual of the reconstruction of the atmospheric muon flux observed in a
precision experiment, by the study of atmospheric neutrino and muon fluxes
response to the variation of hadronic interaction. However, the efficiencty of
this method is largely dependent on the observation site of the atmospheric
muon flux, as the relation of the error of the atmospheric neutrino flux
calculation and the residual of the reconstruction of the atmospheric muon flux
is also largely dependent on the muon observation site, especially for the low
energy neutrinos. We calculate several observation sites, near Kamioka at sea
level, same but 2770m a.s.l.., Hanle India (4500m a.s.l.), and at Balloon
altitude ($\sim$ 32km). Then we estimate how stringently can the atmospheric
muon reduce the error in the calculation of the atmospheric neutrino flux. We
also discuss on the source of error which is difficult to reduce by only the
observation of atmospheric muon.
