PURPOSE: To ensure highly accurate setting and enable to print rules with high quality free of blurring or the like, by providing a fine adjusting mechanism for three axes (axial directions) of X, Y, Z, thereby accomplishing fine adjustment of position required in setting a rule-printing device using a thermal printing head or the like.

CONSTITUTION: A thermal printing part of the head 8 must be brought into contact with a platen 6 at a position P at which the circumference of the platen intersects with Y-axis and the printing part is parallel with X-axis. In addition, the staggering amount between the position P and a position Q for printing by a type through a type bar 3 must be maintained accurately for tabulation printing free of staggering. Further, favorable printing quality can not be obtained if there is an absolute positional stagger between the type-printing position Q and the rule-printing position P. Accordingly, position adjustment in the X-axis direction (the circumferential direction of the platen) of point P is performed by moving a base 21 in the X-axis direction, while position adjustment in the Z-axis direction is performed by moving a base 23 in the Z-axis direction, and position adjustment in the Y-axis direction of the head 8 is so performed that a contact surface of the head 8 makes contact with the point P when the contact surface lies in the tangential plane to the platen 6 at the point P.