A grinding machine including optical detectors for detecting an inclination and a difference of a reference position of the workpiece with respect to a reference position of the grinding machine; an inclinable jig capable of inclining the reference position of the workpiece; controlling members for rotating the inclinable jig; displacement detectors for detecting an inclination of the inclinable jig; and a controlling device for calculating the correction amount of the reference position of the workpiece according to the position information from the optical detectors, providing the control signal to the controlling members in accordance with the calculated value to rotate the inclinable jig, simultaneously receiving the information from the displacement detectors, rotating the inclinable jig until the information from the displacement detectors coincides with the calculated value, and holding the jig. The inclinable jig includes an inclinable member supported rotatably by hydrostatic pressure pads and is capable of finely adjusting and setting the position of the workpiece to be ground.