The three-dimensional linear model of the World ocean climate (with real bottom) is presented. The numerical method is based on the implicit schemes. The equations of heat and salt transport with respect to horizontal coordinates are approximated by the nine-point difference scheme, obtained by the Richardson extrapolation. The second up-wind scheme is used in the vertical coordinate. A series of numerical experiments was carried out till the steady states for 12, 24, 36 vertical levels. The global distribution of temperature and salinity fields is in agreement with observations, though the model does not simulate the Antarctic Intermediate Water and deep water too fresh. After five thousand years of integration, the stationary solution contains oscillations with different periods varying from a few years to hundreds. The influence of the vertical resolution on the average temperature of the ocean is analyzed.