To highly accurately correct a relationship between a camera position coordination system and a spindle position coordination system without placing any burdens on an operator.

An operator sets first to nth calibration positions within the visual field of a CCD camera (S1). A printed circuit board is mounted on a machining base (S2). Initialization is made to calibration position number (i)=1 (S3). The image of the printed circuit board is picked up, and the printed circuit board is carried such that a first reference mark portion (i) comes to the position (i) within the visual field (S4). A spindle is positioned by using the position (i) as a correction hole center instruction position and a calibration hole is drilled (S5). The center position of the drilled calibration hole (i) is measured, and a difference between this hole and the calibration hole center instruction position is calculated (S6). This operation is repeated until the position number (i) reaches the set number (n) of a calibration position (S7 and S8). Based on the difference, the coordinate conversion factor for converting a CCD camera position coordination system into the position of a spindle position coordination system (R, θ) is set (S9). Thus, an operation is automated, and a time for calibration is shortened without placing any burdens on the operator. Calibrating accuracy is improved.