PURPOSE: To carry out correct copying operation by a styrus, even if a large friction is generated between a model, by installing a means for correcting the vertical direction speed so that the influence due to the friction is eliminated, on the basis of the correction data, in the actual copying operation.

CONSTITUTION: The correction data is obtained from the transfer speed (v) of a styrus 2 and the vertical direction speed VN obtained from the deviation displacement Δ, in a correction data calculator 21, and the transfer speed of the styrus 2 and the correction coefficient are memorized in pair into a correction data memory device 22. A correction data read-out device 23 reads out the correction coefficient corresponding to the styrus transfer speed (v) in the copying operation, and a vertical direction speed corrector 24 multiplies the vertical direction speed VN obtained from the calculator 8 by the read-out correction coefficient, and outputs the corrected vertical direction speed VN'. A feed control part 10 drives motors MX, MY, and MZ on the basis of the speed VN' supplied from the corrector 24, copying direction speed VT supplied from a calculator 9, and the positions X, Y, and Z of a tracer head 1 which are supplied from the detector 5. Further, the direction of the speed VN' is set at a right angle for the surface of a model 3.