Abstract: Bar code data read from a bar code card (4) by a bar code reader (1) is inputted to a data processor (3). In this data processor (3), noise included in the bar code data is extracted or detected. The noise is detected by dividing the noise into noise which exists outside of a start guard bar and an end guard bar in a bar code and noise which exists between the start guard bar and the end guard bar. After the noise is detected, the data processor (3) decodes the bar code by ignoring the noise or decodes the bar code after removing the noise to correct the width of each of bars. A game set (5) also performs the same processing as that of the data processor (3) with respect to bar code data inputted from a bar code reader (10). In addition, the game set (5) uses the inputted bar code data for processing for a game.