A printer-plotter includes first and second heads which are supported by a guide rail and are movable along a longitudinal direction of the guide rail, independently. A driving member is supported by the guide rail and configured to move along the longitudinal direction between the first head and the second head. A first connecting mechanism is configured to connect the first head to the driving member detachably. A second connecting mechanism is configured to connect the second head to the driving member detachably. The first head is connected to the driving member by the first connecting mechanism and the second head is separated from the driving member in order to make the first head operate. The second head is connected to the driving member by the second connecting mechanism and the first head is separated from the driving member in order to make the second head operate.