Abstract: There is provided a groove machining tool supported in a holder and caused to move together with the holder in relative fashion along a scheduled scribe line over an integrated thin-film solar cell substrate to form a groove. The groove machining tool includes a tool body supported in the holder, and a blade tip part formed in a distal part of the tool body. The blade tip part includes a blade extending along a direction intersecting a direction of movement of the tool, at a first end along the direction of movement of the tool. The blade is tilted backward from the direction of movement of the tool in relation to a direction orthogonal to the direction of movement of the groove tool, as viewed from a bottom face of the blade tip part.

Abstract: A scribing wheel having a long life with little wear at the blade even when used to scribe a substrate that is relatively hard, such as a ceramic substrate, which can create deep vertical cracks if necessary is provided. A number of grooves 13 are created with predetermined intervals at the blade 12 that is along the ridgeline of the wheel of which the outer diameter is within a range of 1 mm to 5 mm. The depth D of these grooves 13 is 25 ?m or more and the length of the ridgeline 14 between grooves is 25 ?m or more. It is preferable for the pitch P of the grooves 13 to be in a range from 50 ?m to 200 ?m.