The invention provides a fine-adjustment mechanism for a scanning probe microscopy with high rigidity and high degree of measurement accuracy wherein a strain gauge displacement sensor which can be installed in a small space is arranged so that temperature compensation is achieved. The fine-adjustment mechanism composed of a piezoelectric device is provided with at least two-piece electrode. One of the electrodes is configured as a dummy electrode, to which no voltage is applied, and the other electrode is configured as an active electrode which generates strain when voltage is applied. One or two resistors are provided on each of the active electrode and dummy electrode, and a bridge circuit is configured by the resistors.