A three-dimensional microprobe, which is capable of measuring the forces exerting on the probing pin in all directions, is presented. The microprobe is fabricated on stainless steel and is covered by two sets of piezoelectric transducers. One of the transducers drives the probe, and the other senses the dynamic response to identify the contact between the pin and obstacles. A theoretical model is carried out to investigate the transition of the microprobe between contact and non-contact states. Accordingly, a bifurcation diagram is established to provide a design reference for the optimization of driving frequency. A finite element simulation is also carries out for the complete design optimization. Indeed, the fabricated microprobe can be used for the coordinate measurement of the high-aspect-ratio micro-structures.