In recent years a method has been developed by Tomonaga, Schwinger, Feynman, and Dyson to remove self-consistently the divergence difficulties in the quantum electrodynamics with the introduction of the idea of mass and charge renormalizations. Stimulated by this success, applications of this self-consistent subtraction method have been tried by many physicists to other more general systems than that of electron and electromagnetic field, yielding finite results for many processes which had hitherto suffered from divergences. However, there are reported negative examples also, where divergences involved in the reaction of one field on the other can not be concealed in mass and charge (more generally, interaction constant): –as, the anomalous magnetic moment of nucleon due to vector meson with tensor coupling, the induced electric current for vector meson due to fluctuation of radiation field and vacuum polarization, etc. Therefore, the applicability of this method seems to be rather restricted. Here arises a question whether the self-consistent subtraction method would be successful when applied to systems consisting of more than two mutually interacting wave fields, if it is the case for each sub-system composed of two of the constituents. From such a point of view we have treated the problem of the radiative correcion to decay processes. In the first part of this paper two of us reported the result for the decay of a scalar meson interacing with light particles through scalar coupling. The answer was in that case affirmative apart from the lack in uniqueness of the renormalization of the coupling constant. In the present paper we deal with the second order radiative correction to the beta disintegration of nucleon, assuming the Fermi's interaction between necleon and lepton fields, and show that there appears such an ultraviolet divergence as can not be removed by the procedure of renormalization of mass and coupling constant, so far as a single type of coupling is assumed for the decay Hamiltonian. The possibility of compensation of divergenes by mixing several types of coupling is also discussed.