This paper presents calibration software "D-Calib" for multiple cameras, which can calibrate all cameras at the same time with easy operation. Our calibration method consists of two steps: initialization of camera parameters using planar marker pattern, optimization of initial parameters by tracking two markers attached to a wand. By weak calibration and multi-stereo reconstruction by multiple cameras, the initial parameters can be optimized in spite of few markers. Even if the cameras are placed in a large space, the calibration can be achieved by swinging the wand around the space. This method is completed as commercial software which achieves 0.27 % of average errors against the marker pattern size.