US Patent 11833611 Laser machining device

A laser processing apparatus includes a support portion, a laser processing head, a vertical movement mechanism, a horizontal movement mechanism, and a controller. The controller controls starting and stopping of emission of a laser light from the laser processing head based on rotation information in a state where a focusing point is positioned at a position along a circumferential edge of an effective region in a target, while rotating the support portion, to perform a circumferential edge process for forming a modified region along the circumferential edge of the effective region in the target.