  The fluctuations of the cosmic microwave background (CMB) are investigated
for a small open universe, i.e., one which is periodically composed of a small
fundamental cell. The evolution of initial metric perturbations is computed
using the first 749 eigenmodes of the fundamental cell in the framework of
linear perturbation theory using a mixture of radiation and matter. The
fluctuations of the CMB are investigated for various density parameters Omega_0
taking into account the full Sachs-Wolfe effect. The corresponding angular
power spectrum C_l is compared with recent experiments.
