A push portion (10f) is formed on an arm (10c) of a manual lever (10). Formed on a ratchet pawl (17) adapted to reciprocate interlockingly with the manual lever (10) are an elastic portion (17a) adapted to be pushed by the push portion (10f), and a pawl portion (17b) adapted to contact with teeth of a ratchet wheel (19). A printer (P) is mounted to tip ends of the arms (10c, 10d), and the ratchet wheel (19) is integral with a transfer drum (18). In a stroke of gripping the manual lever (10), the elastic portion (17a) is caused to flex, so that the pawl portion (17b) slides toward the teeth of the ratchet wheel. The moment the pawl portion (17b) goes beyond the teeth, a resistance force on the manual lever (10) sharply decreases, so that the printer (P) shockingly abuts against a label to perform printing. When a label tape (12) is set, a bottom cover (14) is opened. The bottom cover (14) can be surely opened by a biasing force, which is stored in elastic portions (15d, 15e) by pushing a finger applying portion (15a) of a latch member (15).