Abstract: [Object] To provide a vacuum pump, a vacuum exhaust device, and a method of operating a vacuum pump that are capable of achieving a stable exhausting operation without causing a step-out. [Solving Means] Provided is a method of operating a vacuum pump including a rotor (21, 22), a drive motor (35), and a magnetic coupling (50) configured to transmit a rotational force of the drive motor to the rotor at a rotational torque equal to or smaller than a first threshold value (Th1). The method includes detecting a load torque of the drive motor (35). The number of revolutions of the drive motor (35) is increased when the load torque is equal to or smaller than a second threshold value (Th2) that is smaller than the first threshold value (Th1). The number of revolutions of the drive motor (35) is reduced when the load torque exceeds the second threshold value (Th2) and is equal to or smaller than the first threshold value (Th1).