  We investigate holographically the entanglement entropy of a nonconformal
medium whose dual geometry is described by an Einstein-Maxwell-dilaton theory.
Due to an additional conserved charge corresponding to the number operator, its
thermodynamics can be represented in a grandcanonical or canonical ensemble. We
study thermodynamics in both ensembles by using the holographic renormalization
and the entanglement entropy of a nonconformal medium. After defining the
entanglement chemical potential which unlike the entanglement temperature has a
nontrivial size dependence, we find that the entanglement entropy of a small
subsystem satisfies the relation resembling the first law of thermodynamics in
a medium. Furthermore, we study the entanglement entropy change in the
nonconformal medium caused by the excitation of the ground state and by the
global quench corresponding to the insertion of particles.

High Energy Physics - Theory