To provide a grinder for improving productivity by reducing a time until a grinding surface of a grinding wheel contacts with a workpiece and grinding actually starts without imparting damage to the workpiece.

A control means 10 includes a storage means for storing the thickness of the workpiece W before processing held at a chuck table 8. When moving a grinding unit 3 by operating a grinding unit feed mechanism 5 while supplying a grinding fluid to the grinding wheel 324 by operating a grinding fluid supply means 4, the control means operates the grinding unit feed mechanism at first feed speed to a feed speed changing position where an interval between the grinding surface of the grinding wheel and the workpiece before processing reaches a predetermined interval operates the grinding unit feed mechanism at second feed speed lower than the first feed speed but higher than grinding feed speed from the feed speed changing position to a grinding wheel rotation speed is reduced to a predetermined value, and feeds the grinding unit at the grinding feed speed to a grinding finishing position.