Using the pump-probe technique with 130 fs laser pulses near 200 nm and near 266 nm the internal conversion of the pyrazine molecule excited to the S-2 state has been studied. The lifetime of the S-2 state due to internal conversion to the lower electronic states is tau(IC)((2)) = (20 +/- 10) fs while the lifetime of the secondarily populated S-1 state is tau(IC)((1)) = (22 +/- 1) ps. The results of femtosecond time-resolved electron spectroscopy directly demonstrate the variation of the electron configuration during the internal conversion: The electron spectrum changes significantly on the fs time scale for pyrazine ions produced by ionization via the S-2 state with pi pi* character and by ionization of S-1 state molecules with n pi* configuration after the internal conversion, respectively. The results obtained confirm theoretical estimations of Domcke and co-workers [J. Chem. Phys. 95, 7806 (1991); J. Phys. Chem. 97, 12466 (1993)] who describe the internal conversion in the pyrazine molecule on the basis of a conical intersection of the corresponding potential energy surfaces. (C) 2000 American Institute of Physics. [S0021-9606(00)00810-2].