In this report I consider dynamic instability when the non-equilibrium neutronization of matter plays the main role. The model of the deflagration supernova has been developed during more than ten year in our group. In 1973 it was shown that thermal flash evolves in the deflagration regime. In our computations the deflagration regime is stipuleted by joint effect of compression of matter and weak shock waves, obtained at the pulsing regime of burning. Fig. 1 shows the graduated growth of entropy in mass zone through passage of weak shock waves.