PURPOSE: To provide a glass plate work device by which constant grinding, polishing or cutting line formation can be applied to a glass plate by keeping contact pressure of a grinding or polishing wheel or a cutter wheel to the glass plate constant.

CONSTITUTION: A glass plate work device 70 has a grinding wheel 46 to apply chamfer work to a glass plate 10, a motor 45 to drive the grinding wheel 46, a motor 17 to move the grinding wheel 46 in the X axis direction and the Y axis direction to position a work part of the grinding wheel 46 at a work point of the glass plate 10 and a pneumatic cylinder device 48 to press the grinding wheel 46 to the glass plate 10, and has a load cell 51 to detect reaction force applied to the grinding wheel 46 from the glass plate 10 and a control valve device 52 to control pressing force to the glass plate 10 of the grinding wheel 46 by the pneumatic cylinder device 48 according to the reaction force detected by the load cell 51.