Let S be an inverse semigroup with an upward directed set of idempotents E. In this paper we define the module topological center of second dual of a Banach algebra which is a Banach module over another Banach algebra with compatible actions, and find it for ℓ 1 (S) * * (as an ℓ 1 (E)-module). We also prove that ℓ 1 (S) * * is ℓ 1 (E)-module amenable if and only if an appropriate group homomorphic image of S is finite.2000 Mathematics Subject Classification. 46H25.