To accurately and efficiently read out a bar code by recognizing and easily correcting the scanning position and width of laser light on a bar code surface in both of manual scanning and automatic scanning.

The bar code reader is provided with a laser diode 2 and a rotary mirror 8 for deflecting laser light emitted from the laser diode 2 to perform scanning and a fine piece (a part to be detected) 20A fitted to the mirror 8 is detected by a photosensor 25 on the reading start position of a bar code 1 by laser light. In the case of automatic scanning, scanning time up to a final reading position is measured after the detection of the fine piece 20A and then the mirror 8 is stopped only for prescribed time. In the case of manual scanning, the rotation of the mirror 8 is locked when a half of the scanning time up to the final reading position is measured after the detection, so that the laser light can be easily recognized.