It is an object of the present invention to improve usability. To meet this objective, a pharmaceutical injection device comprises a main body case (2) having an injection needle insertion and retraction opening (1) through which an injection needle (14) is inserted and retracted； a pharmaceutical syringe mounting component (3) that is provided inside the main body case (2) and onto which a pharmaceutical syringe (4) is mounted； a piston (5) provided movably with respect to the pharmaceutical syringe (4) mounted onto the pharmaceutical syringe mounting component (3)； a drive mechanism (6) for driving the piston (5)； a display component (35) for displaying information related to the injection of a pharmaceutical； a memory (46) that is provided inside the main body case (2) and that stores a preset pharmaceutical injection schedule； and a controller (7) that is electrically connected to the drive mechanism, the display component, and the memory, and resets a current pharmaceutical dose by comparing a planned cumulative pharmaceutical dose, which is a planned cumulative amount of pharmaceutical injected up to the last time on the basis of the pharmaceutical injection schedule stored in the memory, and an actual cumulative pharmaceutical dose, which is a cumulative amount of pharmaceutical actually injected up to the last time.
