In this proposal, we want to study the magnetic behaviour of the [CH3NH3][Cu(HCOO)3] compound. The temperature evolution of this compound shows an anisotropic cell parameter variation, which can be attributed to the geometrical distortion associated to the Jahn-Teller effect. This effect is closely related with the shape of the susceptibility curve which shows a broad maximum around 38 K that probably corresponds with short-range magnetic order. A second magnetic transition occurs at 4K corresponding with a weak ferromagnetic signal due to spin canting or non-compensation of magnetic moments. We ask for D7 instrument in order to determine the behavior of the magnetic signal observed at 38 K. The 3-directional (XYZ) polarization analysis at two different temperatures, 60 and 10 K is a suitable tool to elucidate the occurrence of a 1D-magnetic order. For accomplish this task, we ask for 8 days of polarized neutron beam at D7 instrument operated at 4.8 Å (0.2 < Q < 2.5 Å-1) using the XYZ method.