Abstract: An electric field measuring apparatus includes an electrostatic chuck with a through hole and holding a wafer, a lift pin picking up the wafer, a driver vertically moving the lift pin along the through hole, a probe in the lift pin and having a refractive index changed by an electric field of the wafer, the probe including an electro-optical crystal, an optical waveguide forming at least one internal path of light having a polarization characteristic changed by the changed refractive index between the probe and the wafer, and a control module controlling the lift pin and the driver. The lift pin moves to first and second positions. The control module calculates a strength of the electric field of the wafer, using electric field data measured using the probe at each of the first and second positions.

Abstract: A pin electronics, which inputs and outputs signal from and to an input/output pin of an electric part, provided in a testing apparatus that tests the electric part; including: a current source which outputs desired electric current; a first voltage generator which generates a desired voltage; and a diode bridge, which is connected to each of the current source, the first voltage generator, and the input/output pin of the electric part, that provides the desired electric current to the electric part and provides the desired voltage to the electric part; wherein: the first voltage generator has a current measuring unit that measures an electric current, which is input from the first voltage generator to the diode bridge.