1. A photovoltaic devices inspection apparatus for determining whether a photovoltaic cell of photovoltaic devices is defective or non-defective, the photovoltaic devices inspection apparatus comprising: a power supply configured to apply a forward current to a photovoltaic cell as an inspection-object; a camera configured to photograph the photovoltaic cell when the photovoltaic cell emits light in response to a current applied from the power supply; and an analyzer configured to analyze an image photographed from the photovoltaic cell by using the camera, wherein the analyzer: (a) calculates a threshold value of brightness and darkness based on an average brightness of a region of the photographed image where bright and dark parts are mixed in respect to the photographed image of the photovoltaic cell by using the camera, (b) divides the photographed image into bright and dark regions based on the threshold value of brightness and darkness and displays the bright and dark regions, (c) determines existence of a defect and a defect type for each photovoltaic cell of the photovoltaic device by previously classifying and registering the defect types and comparing a shape of the dark region with the preregistered threshold value of the defect type, (d) enhances the bright and dark regions by binarizing and displaying the bright and dark regions, and (e) determines existence of a defect for each photovoltaic cell of the photovoltaic devices.