An apparatus for laser machining is provided including a stage for supporting a substrate and a controller for generating an error compensation table, a motor driver for moving the stage, and an error compensation unit for generating a table to compensate for an error. The error compensation unit includes a grid plate disposed on the stage and an imaging unit for imaging the grid plate. The motor driver outputs a position synchronization signal to the imaging unit according to a position of the stage. The imaging unit receives the position synchronization signal from the motor driver and images the grid plate while moving the stage.