  We demonstrate how to build a vibrating wire resonator for phonon excitation
in liquid helium. The resonator is designed as a nanoscopic mechanically
flexible beam machined out of a semiconductor/metal-hybrid. Quenching of the
mechanical resonance around 100 MHz by phonon excitation in liquid ^4He at 4.2
K is shown. First measurements operating the nano-resonator in a dilution of
^3He/^4He at 30 mK are presented.
