  We introduce a new method to detect the absolute neutrino mass scale. It uses
a macroscopic mass of tritium source. We explain that the neutrino mass can be
measured by scaling the mass difference of the source between initial and final
state, and its heat value. This method is free from the electron energy
resolution limit and the statistical error. We estimate the required accuracy
to measure the neutrino mass. We also report that the {u,d} component of the
CKM matrix, |V(ud)| may be determined in 10^-6 accuracy as an application of
this work.
