  The assessment of neutrino absolute mass scale is still a crucial challenge
in today particle physics and cosmology. Beta or electron capture spectrum
end-point study is currently the only experimental method which can provide a
model independent measurement of the absolute scale of neutrino mass. HOLMES is
an experiment funded by the European Research Council to directly measure the
neutrino mass. HOLMES will perform a calorimetric measurement of the energy
released in the electron capture decay of the artificial isotope $^{163}$Ho. In
a calorimetric measurement the energy released in the decay process is entirely
contained into the detector, except for the fraction taken away by the
neutrino. This approach eliminates both the issues related to the use of an
external source and the systematic uncertainties arising from decays on excited
final states. The most suitable detectors for this type of measurement are low
temperature thermal detectors, where all the energy released into an absorber
is converted into a temperature increase that can be measured by a sensitive
thermometer directly coupled with the absorber. This measurement was originally
proposed in 1982 by A. De Rujula and M. Lusignoli, but only in the last decade
the technological progress in detectors development has allowed to design a
sensitive experiment. HOLMES plans to deploy a large array of low temperature
microcalorimeters with implanted $^{163}$Ho nuclei. In this contribution we
outline the HOLMES project with its physics reach and technical challenges,
along with its status and perspectives.
