Multiferroic materials show, in a single phase, at least two ferroic properties. The latter are are (anti-)ferroelectricity, (anti-)ferromagnetism or (anti-)ferroelasticity. Interesting applications can use the properties of multiferroics, especially with those presenting magnetic and electric coupling. The ability of controlling a magnetic field with an electric field, using the magnetoelectric coupling, could have interesting applications in spintronics (spin transport electronics), electronic memory devices and sensors. The aim of this project was to familiarize with the use of a cryogenic magnetometer and to perform magnetic and magnetoelectric susceptibility measurements on a sample of Ba2CoGe2O7 . It is a two-dimensional antiferromagnet, in which the magnetoelectric coupling has been discovered in 2008.