The present invention provides a mask, on which a preset pattern is provided. First test patterns for determining an amount of a position offset of the mask during its movement are provided on the mask at a first side of the preset pattern and a second side of the preset pattern opposite to the first side, respectively. When being moved in a direction from the first side to the second side by a standard distance, the mask can determine whether a position offset occurs to the mask during its movement, and determine an amount of the position offset if a position offset occurs. Thus, the position offset of the mask can be corrected, thereby obtaining an accurate predetermined pattern on a glass substrate.