To provide a grinder and a grinding method using it for performing rough machining and finishing inexpensively, easily, and highly accurately using a conventional grinder and measuring the shape of a workpiece on a machine inexpensively, easily, and precisely.

The grinder 10 has a spindle 12 disposed rotatably in a fixed frame 11 and a grinding member 13 mounted with the shaft core aligned to the spindle 12, and polishes the workpiece 16 with the grinding member 13. The grinding method using the grinder comprises a first process for applying the rough machining to the workpiece 16 using a grinding wheel 27 for rough machining of the grinding member 13, a second process for finishing the workpiece 16 using a grinding wheel 23 for finishing of the grinding member 13 disposed concentrically, and a third process for measuring the surface roughness of the workpiece 16 after the polishing with a roughness gauge 17 mounted to a fixed frame 11.