To always wipe a glass panel with a clean cloth part by responding to cloth contamination, by arranging a soft cushion body along the lengthwise direction of a body case, and positioning a cloth delivered from a delivery device between the cushion body and the glass panel.

A soft cushion body 15 with a plurality of wash water delivery holes 15a is laid along the lengthwise direction of a body case 10. A cloth 17 is positioned between the soft cushion body 15 and a glass panel, and paid out from a delivery device 26. In addition, a wash water storage chamber 21 is kept communicated to the soft cushion body 15, and wash water contained in the wash water storage chamber 21 is fed to a plurality of the wash water delivery holes 15a of the soft cushion body 15 on the operation of a wash water feed pump 18. According to this construction. the glass panel can always be wiped by use of a clean cloth part 17, responding to the contamination of the cloth 17.