A bar code reader for reading a bar code 30 composed of a plurality of white bars and a plurality of black bars, includes a generating unit 8 for generating bar width values respectively showing a width of the read bars, a judging unit 12 for judging based on the bar width values whether or not the read bar code satisfies a predetermined standard condition, and a converting unit 12 for converting the read bars into a plurality of bars in which a black-and-white-inverted bar is interposed between the conversion-target color bars. If the judging unit judges that the bar code does not satisfy the predetermined standard condition, the converting unit converts any one of the white and black bars constituting the bar code, and thereafter the judging unit makes a re-judgement. The bar code reader is capable of demodulating the bar code which has been abnormally read by presuming and compensating the bars read apparently as a single bar to a plurality of bars.