PURPOSE: To eliminate possible missetting by performing approaching/separating operation of a recording section and locking of units with one lever simultaneously to simplify the mechanism structure while facilitating the setting work.

CONSTITUTION: The approaching/separating operation of a thermal head 23 with respect to a platen roller 12, the approaching/separating operation of a roller such as pinch rollers 28 and 29 with respect to tension rollers 21 and 27 and the locking operation of both in the engagement of both the units U1 and U2 are performed simultaneously with a lever 33. A lock member 32 and the lever 33 are fastened on a shaft 31 mounted rotatably on a side plate 2 of the unit U2 and an engaging pin 35 to be in cooperation with the lock member 32 is fastened on a side plate 1 of the unit U1.