DAO attack showed that formal verification of smart contracts is an important issue that should be addressed to prevent irreversible consequences due to design faults activation in Blockchain applications. This paper proposes a modeling method of an Ethereum application based on smart contracts, with the aim of applying a formal method, namely Model-Checking, to verify that the application implementation complies with its specification, formalized by a set of temporal logic propositions. NuSMV tool has been chosen to support this first approach. The proposed model template is shaped by three layers capturing respectively the behavior of Ethereum blockchain, the smart contracts themselves and the execution framework. The approach is illustrated by a case study coming from energy market field.