An electro-optical inspection apparatus is provided that is capable of preventing adhesion of dust or particles to the sample surface as much as possible. A stage (100) on which a sample (200) is placed is disposed inside a vacuum chamber (112) that can be evacuated to vacuum, and a dust collecting electrode (122) is disposed to surround a periphery of the sample (200). The dust collecting electrode (122) is applied with a voltage having the same polarity as a voltage applied to the sample (200) and an absolute value that is the same or larger than an absolute value of the voltage. Thus, because dust or particles such as particles adhere to the dust collecting electrode (122), adhesion of the dust or particles to the sample surface can be reduced. Instead of using the dust collecting electrode, it is possible to form a recess on a wall of the vacuum chamber containing the stage, or to dispose on the wall a metal plate having a mesh structure to which a predetermined voltage is applied. In addition, adhesion of dust or particles can be further reduced by disposing a gap control plate (124) having a through hole (124a) at the center above the sample (200) and the dust collecting electrode (122).