PURPOSE: To machine a curved face in a spectacle lens or the like by means of two-dimensional movements of a work and a grinding wheel relative to each other.

CONSTITUTION: A work 3 is mounted on a face plate 8 provided to a work main spindle 7 and a grinding wheel 2 mounted on a grinding wheel main spindle 12a is made to abut on the work 3 and rotated and, as the angle of rotation of the work main spindle 7 with respect to the work 3 is varied by a work dividing mechanism 9, the work 3 is moved along the direction of the axis of the work main spindle 7 and relative to the axis, and the grinding wheel 2 is moved along the perpendicular direction to the axis of the work main spindle 7 and relative to the axis, whereby a required curved face is formed in the work 3.