A method for processing a plate-shaped workpiece having a division line and a metal member formed on the division line or in an area corresponding to the division line includes a holding step of holding the workpiece on a chuck table with the metal member oriented downward, a first cutting step of cutting the workpiece along the division line by using a first cutting blade, thereby forming a first cut groove having a bottom not reaching the metal member, and a second cutting step of cutting the workpiece along the first cut groove by using a second cutting blade, thereby forming a second cut groove fully cutting the workpiece along the division line so as to divide the metal member. The second cutting step includes supplying a cutting fluid containing an organic acid and an oxidizing agent to the workpiece.