Cannabis is usually mixed with tobacco and rolled in a joint, but it can be smoked in a pipe or it can also be consumed as a tea or in cake form.
Is Business Expected to Plummet?
Jason den Enting has been managing the Tweede Kamer for more than six years without any problems.
He said that his European customers are the ones to be most affected by the new rule.
"Our guests from America are usually the ones to smoke marijuana pure or in a pipe. They're more used to that than our clients from here. Our local patrons traditionally prefer their cannabis joints mixed with tobacco, because it isn't that strong then."
Asked whether he expects business to plummet, den Enting said, "I don't think so, but it might be less fun in the future.
"So far," he said, "we're taking pride in providing a convivial atmosphere, We don't want to become a drug takeaway. Our guests like to come here for the social contacts, chatting with each other, reading newspapers or talking about politics.
"Now," he said, "that atmosphere is likely to be destroyed by an absurd decision."