To provide a bar code reader having an excellent characteristic that a bar code surface having irregularities can be precisely and quickly read, and a bar code reading method using this bar code reader.

The bar code reader comprises a transparent plate located vertically to the path of light in a place separated from a bar code reading light source and pressed to the bar code surface to extend the irregularities of the bar code surface. The transparent plate is preferably formed of an acrylic board. In this bar code reading method, this bar code reader is used, the irregularities of the bar code surface is extended by pressing the transparent plate to the bar code to read the bar code. Concretely, the bar code surface is located on the outer surface of a flexible bag, more concretely, the bag is a flexible container, and further more concretely, the bag is a flexible container containing pellets of synthetic resin.