Check the Eurolines site to get schedules and book.
Yes, both cities have airports, of course, and the nonstop flight takes just under an hour. KLM is the only one that goes nonstop, and they do it many times each day, but sale fares on this route are very rare indeed, and nonstop flights, one-way are usually about €300, though round-trips are usually cheaper, at about €200 for both legs.
Still, you’d have to be a business traveler or a crazy person in order to consider flying between these two. The trip to the airport plus the early check-in time will make going from city to city take at least 4 hours when you add it all up, so the train and even the bus will actually be faster.
