In this paper, we investigate a system of quantum electrodynamics with cutoffs. The total Hamiltonian is defined on a tensor product of a fermion Fock space and a boson Fock. It is shown that, under spatially localized conditions and momentum regularity conditions, the total Hamiltonian has a ground state for all values of coupling constants. In particular, its multiplicity is finite. MSC 2010 : 47A10, 81Q10. key words : Fock spaces, Spectral analysis, Quantum Electrodynamics. [T, J 0 ]h [T, J ∞ ]h , h ∈ D([T, J 0 ]) ∩ D([T, J ∞ ]).(ii) Fermion Fock Space on X ⊕ X Let X be a complex Hilbert space. Let J f = J 0 f J ∞ f , J 0 f , J ∞ f ∈ L(X) and B f = B 0 f B ∞ f , B 0 f , B ∞ f ∈