In this paper, we give a necessary and sufficient condition for which a finitely generated group has a property like Kazhdan's Property (T ) restricted to one isometric representation on a strictly convex Banach space without non-zero invariant vectors. Similarly, we give a necessary and sufficient condition for which a finitely generated group has a property like Property (F H) restricted to the set of the affine isometric actions whose linear part are one isometric representation on a strictly convex Banach space without non-zero invariant vectors. If the Banach space is the ℓ p space (1 < p < ∞) on a finitely generated group, these conditions are regarded as an estimation of the spectrum of the p-Laplace operator on the ℓ p space and on the p-Dirichlet finite space respectively.Mathematics Subject Classification (2010). Primary 20F65; Secondary 46B04, 47H10.