A laser projection method including the steps of: irradiating, from a laser projection unit, a workpiece that is a measurement object, with a laser while controlling a plurality of mirror angles; imaging the workpiece with a stereo camera, extracting a contour of the workpiece, and calculating a three-dimensional coordinate; calculating a positional relationship between the laser projection unit and the workpiece by comparing the calculated three-dimensional coordinate of the workpiece contour with the minor angle; and performing coordinate transformation of CAD data information and drawing CAD data from the laser projection unit to the workpiece, based on the positional relationship between the laser projection unit and the workpiece. The machining method including the steps of: selecting a component of a tool; assembling the component; imaging the tool assembled; and determining whether or not a desired tool has been assembled.