A printing unit comprises: a head unit; and a platen unit to be combined with the head unit. The platen unit includes: a pair of shaft support portions configured to individually support both end portions of the platen roller; and a coupling portion configured to bridge the pair of shaft support portions. The head unit includes an abutment portion provided to the head unit, which is configured to come into abutment against the coupling portion of the platen frame when the platen frame is located at the mounting position. A pressure-applying mechanism is provided between the platen frame and the subframe, which is configured to apply a pressure to the platen frame toward the abutment portion.