There is provided a navigation route generation device with which a host moving body can be navigated by offsetting it parallel to a line on the current travel direction of the host moving body by a simple operation, without changing the preset destination or bearing. A plotter that is part of an automatic steering system of a ship comprises a current route acquisition component, a parallel route generator, and a navigation route setting component. The current route acquisition component acquires the travel direction of the host ship. The parallel route generator generates a parallel route, which is a route that is parallel to the travel direction acquired by the current route acquisition component. The navigation route setting component sets the parallel route generated by the parallel route generator to the navigation route of the host ship.