The stability of the shape of crystal growth face in a two-dimensional mathematical model of crystal growth from a solution under microgravity is studied. It is proved that the stable shape of crystal growth face does exist, which is a suitably shaped curve with its upper part inclined backward properly. The stable shapes of crystal growth faces are calculated for various values of parameters, Ra, Pr, Sc, and L. It is shown that the stronger the convection relative to the diffusion in solution, the more backward the upper part of the stable crystal growth face is inclined.