Magnetic dipolar coupling leads to low-energy excitations in magnetic materials named as magnetostatic waves (MSW). The typical energy of these excitations is of the order of a few tens of μeV. We show that working in grazing incidence in a reflectivity geometry makes it possible to study these very low-energy excitations. We present a neutron set-up which allows to study these excitations. The studied samples were permalloy thin films. The MSW were either thermally excited or induced by a microwave (MW) field and the off-specular neutron reflectivity was measured. We have not been able to measure any inelastic scattered signal, even with a large MW excitation (1W input).