We shall use the Binet–Minc formula in the theory of permanents to prove David Richman's theorem: LetGbe a finite group acting onA≔R[a1,…, ar], whereRis any commutative ring with 1/|G|!∈R. Then the ring of invariantsAGis generated overRby ∑σ∈Gσ(aα11aα22···aαrr), where α1+···+αr⩽|G|. Applications of permanents to other problems related to invariants are given also.