Abstract: A grinding apparatus suitable for use in forming a straight groove on the surface of a work to be processed includes a carriage provided to be movable along a predetermined path in a reciprocating manner between a first end position and a second end position. Each of the first and second end positions is defined as a loading/unloading position. A pair of finish grinding discs is located at the center of and on both sides of the predetermined path. A pair of rough grinding discs is located between the first end and center positions of the path and another pair of rough grinding discs is similarly located between the second end and center positions of the path. Each of the grinding discs is shiftable in positions between advanced and retracted positions in the direction transverse to the predetermined path.