A new scanning probe microscope based on a scanning tunneling microsco
pe (STM) and a frequency shift of an AT cut quartz resonator has been
developed. The quartz resonator coupled to a STM sample is oscillated
at its resonance frequency. The shift of the resonance frequency corre
sponds to the strength of the shearing stress in the sample, and is ca
used by the shearing force interaction between the STM tip and the sam
ple under the tip scanning. The preliminary images presented show simu
ltaneously STM surface topographies and the changes of subsurface shea
ring stresses in gold thin films. The sensitivity of our microscope is
. 0.30 N/m for a 0.2-Hz frequency shift of the quartz crystal resonanc
e frequency.