A voltage and displacement sensitive probe with an electro-optic crystal, electrically conductive transparent films and adhered to a pair of parallel surfaces on the electro-optic crystal, a transparent elastic film which circumferential portion is bonded to the frame and which is symmetric with respect to any plane through the axis thereof, a probing needle bonded at its reflective bottom surface to the central portion on the film, a holder for holding the electro-optic crystal and the transparent elastic film via frame concentrically, a lead for grounding, and electrically conductive films for connecting between the films. Displacement detection of the probing needle is based upon the change in the length of the path of the light travelling through the electro-optic crystal being reflected by the surface and travelling in reverse direction. Voltage detection of the probing needle is based upon the phase difference between the two linearly-polarized light components.