PURPOSE: To obtain a large head gap by providing a link mechanism moving a platen so as to separate the same from a printing head when the printing head is moved from the platen.

CONSTITUTION: When a carrier shaft 18 is rotated from the approach state of a printing head 21 and a platen 19, the printing head 21 is moved in the direction separated from the platen 19 and the platen 21 is moved in the direction separated from the printing head 21. Therefore, an adjustable head gap is determined on the basis of the quantity of eccentricity of a first eccentric part 18 and the moving quantity of a link mechanism 22 based on the eccentricity of a second eccentric part 18b and the adjusting quantity of the head gap can be increased. Therefore, the optimum head gap is ensured even when printing is applied to thick paper to perform good printing. Next, the printing head 21 and the platen 19 are moved in a mutually approaching or separating direction accompanied by the rotation of the carrier shaft 18.