  The HOLMES experiment will perform a precise calorimetric measurement of the
end point of the Electron Capture (EC) decay spectrum of 163Ho in order to
extract information on neutrino mass with a sensitivity below 2 eV. In its
final configuration, HOLMES will deploy 1000 detectors of low-temperature
microcalorimeters with implanted 163Ho nuclei. The baseline sensors for HOLMES
are Mo/Cu TESs (Transition Edge Sensors) on SiNx membrane with gold absorbers.
Considering the large number of pixels and an event rate of about 300 Hz/pixel,
a large multiplexing factor and a large bandwidth are needed. To fulfill this
requirement, HOLMES will exploit recent advances in microwave multiplexing. In
this contribution, we present the status of the activities in development, the
performances of the developed microwave-multiplexed readout system, and the
results obtained with the detectors specifically designed for HOLMES in terms
of noise, time, and energy resolutions
