To enhance polishing efficiency by continuously processing a work without replacing a grinding wheel.

This polishing device 200 has a grinding wheel unit 210 having a grinding wheel driving unit 240 on a grinding wheel carrying unit 220 movable in the Y axis direction, and a work unit 260 for arranging a work installing unit 280 capable of whirling in an XY plane on a work carrying unit 270 movable in the X axis direction; and polishes the work 60 installed in the work installing unit 280 by the grinding wheel 50 arranged in the grinding wheel driving unit 240. The grinding wheel unit 210 is arranged in a plurality in parallel.