We present a model from which the angular and depth dependent atmospheric &ggr; rays can be derived in the energy range of 0.3-10 MeV at &lgr;=40 ¿. The model consists of an isotropic source function which depends on depth and energy expressed in the form S(E,x) =S0(E)x+c(E)x2>e-x/p(E) photons/(g air s MeV) and is determined semiempirically. We determined source strengths for 38 predicted atmospheric &ggr; ray lines and for 10 different energies in the continuum. For the continuum a diffuse cosmic flux, consistent with the Apollo 15/16 data, is assumed in order to fit the measured data above 10 g/cm2. Total and directional fluxes are computed at two different atmospheric depths. The computed flux compares well with other measurements and theoretical calculations.