An attitude control device and a precision machining apparatus capable of accurately controlling the attitude of an object mounted on the attitude control device according to grinding stages. The attitude control device is constituted by a first flat-plate member 21 and a second flat-plate member 22 disposed in parallel with the first flat-plate while being spaced apart from the same by a distance L. A spherical member 3 is interposed between the first and second flat-plate members 21, 22 while fitting its portions in recesses 21a, 22a respectively formed in the first and second flat-plate members 21, 22. A first actuator 4a expandable in a Z-axis direction perpendicular to a plane defined by an X-axis and a Y-axis is interposed between the flat-plate members. Second actuators 4b, 4b expandable in a suitable direction in the plane defined by the X-axis and the Y-axis are connected to the second flat-plate member 22. The second flat-plate member 22 is movable relative to the first flat-plate member while being in an attitude with an object mounted thereon. The spherical member 3 is bonded to the first and second flat-plate members 21, 22 by an adhesive 6 elastically deformable.