A machine tool comprising: a workpiece holding unit (20, 30) configured to hold a workpiece; a tool holding unit configured to hold a tool; wherein at least one of the workpiece holding unit (20, 30) and the tool holding unit are configured to be drivingly rotated, and at least one of the workpiece holding unit (20, 30) and the tool holding unit are configured to be drivingly moved in a predetermined direction so as to machine the workpiece with the tool, and wherein the machine tool comprises a plurality of temperature sensors (81 to 90) attached to members constituting the machine tool; an environmental temperature system thermal displacement amount estimation unit configured to calculate an environmental temperature system thermal displacement amount (321, 322, 323) due to a heat source existing outside the machine tool, based on temperature values each measured by a corresponding one of the plurality of temperature sensors (81 to 90); characterised by a correction magnification processing unit configured to calculate an environmental temperature system thermal displacement correction amount (A$HCX, A$HCY, A$HCZ, 351, 361, 371) by multiplying a calculation-based thermal displacement correction amount (327, 328, 329) for compensating the environmental temperature system thermal displacement amount (321, 322, 323) by a correction magnification (B, Bx, By, Bz); a correction magnification adjustment operation unit (470, 471) configured to adjust the correction magnification (B, Bx, By, Bz) when a worker is operating a correction magnification increase/decrease switch; a driving system thermal displacement amount estimation unit configured to calculate a driving system thermal displacement amount (311, 312, 313) due to a heat source included in the machine tool itself, based on a rotation driving state and a movement driving state of each of the workpiece holding unit (20, 30) and the tool holding unit; and a thermal displacement correction amount addition unit configured to calculate and output a total thermal displacement correction amount (331, 332, 333) by adding the environmental temperature system thermal displacement correction amount (A$HCX, A$HCY, A$HCZ, 351, 361, 371) to a driving system thermal displacement correction amount (317, 318, 319) for compensating the driving system thermal displacement amount (311, 312, 313), and wherein thermal displacement correction control is performed based on the total thermal displacement correction amount (331, 332, 333). a workpiece holding unit (20, 30) configured to hold a workpiece; a tool holding unit configured to hold a tool; wherein at least one of the workpiece holding unit (20, 30) and the tool holding unit are configured to be drivingly rotated, and at least one of the workpiece holding unit (20, 30) and the tool holding unit are configured to be drivingly moved in a predetermined direction so as to machine the workpiece with the tool, and wherein the machine tool comprises a plurality of temperature sensors (81 to 90) attached to members constituting the machine tool; an environmental temperature system thermal displacement amount estimation unit configured to calculate an environmental temperature system thermal displacement amount (321, 322, 323) due to a heat source existing outside the machine tool, based on temperature values each measured by a corresponding one of the plurality of temperature sensors (81 to 90); characterised by a correction magnification processing unit configured to calculate an environmental temperature system thermal displacement correction amount (A$HCX, A$HCY, A$HCZ, 351, 361, 371) by multiplying a calculation-based thermal displacement correction amount (327, 328, 329) for compensating the environmental temperature system thermal displacement amount (321, 322, 323) by a correction magnification (B, Bx, By, Bz); a correction magnification adjustment operation unit (470, 471) configured to adjust the correction magnification (B, Bx, By, Bz) when a worker is operating a correction magnification increase/decrease switch; a driving system thermal displacement amount estimation unit configured to calculate a driving system thermal displacement amount (311, 312, 313) due to a heat source included in the machine tool itself, based on a rotation driving state and a movement driving state of each of the workpiece holding unit (20, 30) and the tool holding unit; and a thermal displacement correction amount addition unit configured to calculate and output a total thermal displacement correction amount (331, 332, 333) by adding the environmental temperature system thermal displacement correction amount (A$HCX, A$HCY, A$HCZ, 351, 361, 371) to a driving system thermal displacement correction amount (317, 318, 319) for compensating the driving system thermal displacement amount (311, 312, 313), and wherein thermal displacement correction control is performed based on the total thermal displacement correction amount (331, 332, 333).