A roundness measuring machine includes: a base; a table rotatable relative to the base; a probe configured to scan a surface of a workpiece mounted on the table; a motor configured to rotate the table; and a control device configured to control a rotation of the motor. The control device includes: a starting current detector configured to detect a starting current of the motor; and an acceleration/deceleration time setting unit configured to detect at least one of acceleration time and deceleration time for the motor in accordance with the starting current. The roundness measuring machine can suitably set the acceleration time and the deceleration time for the motor corresponding to the inertia moment of the workpiece mounted on the table.