The hydrogenation of TbNi0.4Co0.6 was studied by means of neutron diffraction and calorimetric method with use of the differential heat-conducting Tian-Calvet type calorimeter. It was determined that TbNi0.4Co0.6H3.8 crystallized in orthorhombic CrB-type structure (S.G. Cmcm). The hydride formation is accompanied with strong lattice expansion. In the structure TbNi0.4Co0.6D3.4 deuterium atoms occupy tetrahedral 8f-intersices, trigonal bipyramidal 4c-interstices and octahedral 4b-interstices. Dependence of the differential molar enthalpy of absorption (ΔHabs) vs. the hydrogen concentration in the metallic matrix was obtained at 50°C. It was ascertained that in the range of 0<X<2.0 (X=H/ TbNi0.4Co0.6) ΔHabs =-102.0±2.3 kJ mol-1H2. The value of the integral enthalpy of hydrogen absorption by TbNi0.4Co0.6 equals -99.5kJ mol-1H2 for the composition TbNi0.4Co0.6H3.8.