METHOD OF PROCESSING WORKPIECE

To provide a method of processing a workpiece that can efficiently form a cross section of a corner part of the workpiece.SOLUTION: A method of processing a workpiece includes a grinding step ST11 of forming a circular recessed part and a ring-shaped projection part by grinding a central part of a reverse surface of the workpiece held on a holding table with a grinding wheel, a moving step ST12 of relatively moving the grinding wheel and the holding table to a position where a rotation path of a grinding grindstone passes through the ring-shaped projection part after performing the grinding step ST11, a cross section forming step ST13 of forming a cross section of a ring-shaped projection part by grinding the ring-shaped projection part by at least a height of the ring-shaped projection part or more with the grinding wheel without rotating the holding table and with the grinding wheel rotating after performing the moving step ST12, and a shape verifying step ST14 of verifying a shape of a corner part formed by a bottom surface of a circular recessed part and an inner peripheral surface of a ring-shaped projection part by imaging or observing the cross section.SELECTED DRAWING: Figure 1 【課題】被加工物の角部分の断面をより効率的に形成することができる被加工物の加工方法を提供すること。【解決手段】被加工物の加工方法は、研削ホイールで保持テーブルに保持された被加工物の裏面の中央部を研削して、円形凹部とリング状凸部を形成する研削ステップＳＴ１１と、研削ステップＳＴ１１の実施後に、研削ホイールと保持テーブルとを、研削砥石の回転軌道がリング状凸部を通る位置に相対的に移動させる移動ステップＳＴ１２と、移動ステップＳＴ１２の実施後に、保持テーブルを回転させず、研削ホイールを回転させた状態で、研削ホイールでリング状凸部を少なくともリング状凸部の高さ以上研削し、リング状凸部の断面を形成する断面形成ステップＳＴ１３と、断面を撮像または観察し、円形凹部の底面と、リング状凸部の内周面とが成す角部分の形状を確認する形状確認ステップＳＴ１４と、を備える。【選択図】図１