A specific heat calorimeter for the temperature range 0.07–1.3 K with a novel sample support of four commercial pencil leads is described. It is shown that this support substantially reduces the vibrational heat input to the sample assembly. The thermal shield of the calorimeter is vacuum tight to allow measurements with gas adsorbing samples. We estimate and derive expressions for the temperature dependence of the thermal conductances of the AuCu thermal link and of the pencil leads support.