To provide a polishing method, a polishing condition calculation method and a polishing device avoiding generation of big waviness without reducing polishing efficiency.

When a polishing member 42 is pressed to a surface 11 to be polished while rotating it, it is moved between both ends of the surface 11 to be polished in a main scanning direction and it is moved in a sub-scanning direction perpendicular to the main scanning direction by a pitch 82 every when movement is completed to the end part to perform polishing of the surface 11 to be polished, after the polishing condition including a value of the pitch 82 and an allowance value regarding the waviness indicating recession/projection of the surface 11 to be polished is input, simulation of polishing is performed based on the polishing condition. Information required for determining whether or not the polishing is allowed such as the maximum recession/projection difference of the waviness is calculated, it is determined whether or not the maximum recession/projection difference of the waviness is larger than an allowance value. When the maximum recession/projection difference of the waviness is not more than the allowance value, the polishing is allowed, and when the maximum recession/projection difference of the waviness is larger than the allowance value, the optimum value of the pitch 82 is output to promote correction of the input pitch 82.