Simulations based on molecular dynamics (MD) are an important tool in structural biology. In the field of lipid membrane research, MD represents a major tool as it grant access to atomic level features of the membrane difficult to access by experimental means. In this chapter we describe step by step how to simulate a membrane in silico. The explanation comprehends from the initial set up of a membrane system to its analysis passing through the simulation itself. Most of the tasks described here are performed using the Gromacs simulation suite, a widely used software for molecular modeling and simulations. In the selected example the attention is focused on a single component lipid bilayer composed of DPPC, one of the most studied lipid species.