The probe apparatus has a probe (first metal plate) as a signal terminal and a probe (second metal plate) as a ground terminal. A probe holder has a holder main body formed of a conductor, clamps that are formed of a dielectric and capable of clamping the probes, and a fixing member and a male screw (or “fixture”) capable of fixing both clamps, which have clamped the probes, to the holder main body. The probes are clamped by the two clamps in a state where the probes have been aligned along the plate surface direction, parts at front-end portion sides of the probes protrude from the two clamps, and the parts at front-end portion sides are capable of elastic deformation along the plate thickness direction.