  A new calculation of the atmospheric fluxes of cosmic-ray hadrons and muons
in the energy range 10-10^5 GeV has been performed for the set of hadron
production models, EPOS 1.6, QGSJET II-03, SIBYLL 2.1, and others that are of
interest to cosmic ray physicists. The fluxes of secondary cosmic rays at
several levels in the atmosphere are computed using directly data of the
ATIC-2, GAMMA experiments, and the model proposed recently by Zatsepin and
Sokolskaya as well as the parameterization of the primary cosmic ray spectrum
by Gaisser and Honda. The calculated energy spectra of the hadrons and muon
flux as a function of zenith angle are compared with measurements as well as
other calculations. The effect of uncertainties both in the primary cosmic ray
flux and hadronic model predictions on the spectra of atmospheric hadrons and
muons is considered.
