The simplified analytical solution and experimental study of laminar free convection heat transfer from an isothermal hemisphere in unlimited space have been presented. The solution is based on adaptation of the methods used for inclined isothermal plates. In the proposed solution the control surface of the hemisphere was considered as a small inclined surface. Inclination of this surface was not a constant one but it was a function of azimuth angle. The result of theoretical consideration is presented in the relation of Nusselt and Rayleigh numbers : Nu = 0.533 x Ra-1/4. The comparison of theoretical solutions with experimental results presented in this paper and results of other authors shows good agreement.