PURPOSE: To execute automatic reading matched with the flow of an automatic manufacturing line of a bottle and to quickly prevent the generation of a defective by detecting the leading position of an identification mark and executing a correction in accordance with the position and the size of each character, etc.

CONSTITUTION: A bottle 1 is placed on a rotary table 4 in an erecting state, and a neck part 3 on which the identification mark 2 is displayed is set to the same height position of a detection light 7 between a projector 8 and an image sensor 9. Image data from the sensor 9 is inputted to a character recognition processing part 10, and each character of the mark 2 is recognized and displayed 11. In this case, the bottle 1 is rotated in the peripheral direction, and at the time point when the leading character of the mark 2 goes into a detection window 21, the rotation of the bottle 1 is stopped, the position of the leading character is detected, the bottle 1 is rotated again, and while allowing it to correspond to the size and the position of each character, and while correcting the position and the size of the read window, read is executed.