A sheet identification apparatus comprising: a selection parameter holding module configured to store a selection area and an image corresponding to the selection area, the selection area being used for identification and selected from among a plurality of areas of an image which is used as a reference when a sheet is to be identified; an image input module configured to input an image of a fed sheet; an area dividing module configured to divide the image input by the input module into predetermined areas; characterized by: a feed state detecting module configured to detect a feed state of the sheet that is being fed; a conversion module configured to convert the image of the selection area stored in the selection parameter holding module, based on a skew amount detected (ST 71) by the feed state detecting module; an identification result acquiring module configured to perform an identification between the image of the selection area converted by the conversion module and an image of an area corresponding to the selection area, and to obtain an identification result for each image; and an identification result determining module configured to determine an identification result of the whole portion, based on the identification result acquired by the identification result acquiring module for each image. a selection parameter holding module configured to store a selection area and an image corresponding to the selection area, the selection area being used for identification and selected from among a plurality of areas of an image which is used as a reference when a sheet is to be identified; an image input module configured to input an image of a fed sheet; an area dividing module configured to divide the image input by the input module into predetermined areas; characterized by: a feed state detecting module configured to detect a feed state of the sheet that is being fed; a conversion module configured to convert the image of the selection area stored in the selection parameter holding module, based on a skew amount detected (ST 71) by the feed state detecting module; an identification result acquiring module configured to perform an identification between the image of the selection area converted by the conversion module and an image of an area corresponding to the selection area, and to obtain an identification result for each image; and an identification result determining module configured to determine an identification result of the whole portion, based on the identification result acquired by the identification result acquiring module for each image. a feed state detecting module configured to detect a feed state of the sheet that is being fed; a conversion module configured to convert the image of the selection area stored in the selection parameter holding module, based on a skew amount detected (ST 71) by the feed state detecting module; an identification result acquiring module configured to perform an identification between the image of the selection area converted by the conversion module and an image of an area corresponding to the selection area, and to obtain an identification result for each image; and an identification result determining module configured to determine an identification result of the whole portion, based on the identification result acquired by the identification result acquiring module for each image.