To enhance the accuracy of calibration.

This method calibrates a three-dimensional shape measuring device 100 having an illuminating mechanism 110 illuminating a subject for measurement with a pattern beam, a camera 120 for photographing the subject for measurement, and a calculation means 130 for calculating three-dimensional image data from the image taken. In this case, a gauge 2 with a plurality of indexes 22 in a known arrangement on a plane 21 is moved plural times by known amounts of movement, and an illuminating beam is applied to the plane 21 of the gauge 2 at each movement to photograph the plane 21. A camera parameter is calculated from position coordinates on a three-dimensional coordinate system shown by each index 21 and from position coordinates on the two-dimensional coordinate system of a taken image which correspond to the above position coordinates, and a projector parameter is calculated from position coordinates on the three-dimensional coordinate system and from position coordinate on a one-dimensional coordinate system on which the positions of the position coordinates on the three-dimensional coordinate system are illuminated.