The model of the vacancies formation in a crystal grown up from melt, as a result of its leaky packing at crystallization is offered. The dependence of the vacancies concentration from growth rate of an ingot from melt (vc), a gradient of temperatures at the front of crystallization (G) and parameters of diffusion and drift carrying over of vacancies in a hot zone of a crystal is calculated. It is shown that the vacancy crystal growth occurs, if Voronkov parameter £, is c >Si, where £ is ^-т^, г) is G ьi 1-п kT 2concentration of atoms in melt and a crystal accordingly, els is an energy of crystallization of atoms, Dls is a diffusion factor on a border of melt and crystal. The offered model allows to estimate modes of an ingot growth from melt.