To provide a V-shaped air knife, of a glass substrate washing machine, which is free from the generation of a liquid residue in the center part, in the width direction, of the glass substrate.

(1) The V-shaped air knife 41 is fitted above the central position (X axis) in the width direction of the glass substrate in the way that the apex (C) of the V-shaped bend part is opposed to the conveyance direction of the glass substrate. (2) At the apex (C), a central air jet part 42 is disposed with an interposing beam 43 for removing a cleaning fluid present in the center part in the width direction of the glass substrate before removing the cleaning fluid by the air knife, during removing the cleaning fluid from the surface of the glass substrate. Besides, the width W1 of the central air jet part 42 is not less than 40 mm and the width W2 of the beam 43 is not more than 50 mm.