The wafer trimming device includes a chuck table configured to hold a target wafer via suction, thereby fixing the target wafer, a notch trimmer configured to trim a notch of the target wafer, and an edge trimmer configured to trim an edge of the target wafer. The notch trimmer includes a notch trimming blade configured to rotate about a rotation axis perpendicular to a circumferential surface of the target wafer. The edge trimmer includes an edge trimming blade configured to rotate about a rotation axis parallel to the circumferential surface of the target wafer.