To provide a thermal displacement correcting method and the like of a machine tool capable of highly accurately correcting thermal displacement with a simple construction.

A supporting rigidity estimating part 54 estimates supporting rigidity Kh in a horizontal direction and supporting rigidity Kv in a vertical direction changed by passing time to a column 10 on the basis of a thermal extension amount ΔL and a temperature change amount Δt of a member 15 (the column 10) acquired by a thermal extension amount acquiring part 52 and a temperature change amount acquiring part 53. When the supporting rigidities Kh and Kv greatly affecting an attitude of the column 10 are changed by passing time, the supporting rigidity estimating part 54 once estimates supporting rigidities Kh and Kv changed by passing time on the basis of a thermal extension amount ΔL and a temperature change amount Δt and a thermal displacement amount deriving part 55 determines a thermal displacement amount ΔM1h in the horizontal direction and a thermal displacement amount ΔM1v in the vertical direction of the column 10 on the basis of the supporting rigidities Kh and Kv. Thereby, accuracy of the thermal displacement amount ΔM1h in the horizontal direction and the thermal displacement amount ΔM1v in the vertical direction can be heightened and highly accurate thermal displacement correction can be made possible with a simple construction.