To provide a bard code reader which can detect the reading error of a bar code when the bar code is read to collect the charge from a customer.

When the bar codes of plural sheets of charge collection slips having the three-stage or four-stage form bar codes, for example, are read by hand scanner 1 for collection of charges, the read bar codes are stored in a charge store file 3 for each stage and every time the bar codes equivalent to a single sheet of slip are read. Then a CPU 2 detects the reading error of a bar code based on whether the bar code that is read by the scanner 1 is coincident with one of a group of bar codes which are read and stored in the file 3.