Mask inspection apparatus and mask inspection method

According to one embodiment, a mask inspection apparatus includes a decompression chamber, a holder, a light irradiation unit, a detection unit, an electrode, and a control unit. The holder is provided in the decompression chamber and holds a mask. The light irradiation unit irradiates a major surface of the mask held by the holder with a light. The detection unit is provided in the decompression chamber to detect electrons generated when the major surface of the mask is irradiated with the light. The electrode is provided between the holder and the detection unit and guides the electrons in a direction from the holder toward the detection unit. The control unit compares a detection result of the electrons detected by the detection unit with a reference value.