A printing unit includes a thermal head, a platen roller, a head support member and a guide member. The platen roller is abutted against the thermal head with the recording sheet therebetween and rotated to feed the recording sheet. The head support member pivotably supports the thermal head around a pivot shaft so as to move the thermal head toward the platen roller. The head frame pivotably supports the head support member via the pivot shaft and rotatably supports the platen roller. The guide member guides the recording sheet between the thermal head and the platen roller. The thermal head and the guide member are positioned with respect to the head frame through the pivot shaft.