Recent researches show that the beta decay of 13N can affect the electron abundance before the collapse of SNe Ia supernovae. Based on the shell model, the Gamow-Teller transition strengths from ground state to ground state and trom ground state to excited state of 13N are calculated and the results are compared with theoretical results and also with experimental data. The electron capture rates at different temperatures and densities are calculated and the effect of ground state on excited state transition is discussed. It is shown that due to the transition from ground state to excited state, the electron abundance of the SNe Ia supernovae decreases and the contributions are determined mainly by the low-lying excited states.