1. A visual inspection device which compares an image acquired by capturing an inspection object with a group of images of items regarded as non-defective items to make a non-defective/defective determination, the device comprising: an image inputting unit for accepting inputs of a plurality of images constituting a group of images of items regarded as non-defective items; a non-defective item image storing unit for storing these images; a threshold setting unit for setting a defect threshold for detecting a defective portion of an inspection object and setting a determination threshold for making the non-defective/defective determination based on the plurality of images stored in the non-defective item image storing unit; a defective item image storing unit for storing a defective item image which is an image of an item determined as a defective item; a threshold resetting unit for resetting at least the defect threshold by performing non-defective item learning processing based on a plurality of images stored in the non-defective item image storing unit, in a case of acceptance of an additional input of an image acquired by capturing an inspection object, the plurality of images including the image accepted by the additional input; a non-defective/defective determination unit for determining whether or not the defective item image stored in the defective item image storing unit is an image of a defective item based on the set determination threshold; and a determination result displaying unit for displaying a non-defective/defective determination result.