As the flight bans resulting from the cloud of Icelandic volcano ash entered their fourth day, Ramsauer told told broadcaster Deutschlandfunk that it was “politically unfeasible” to weigh up the losses in revenues for airlines against public safety.
“Safety is the top priority,” he said.
Over the weekend, Germany's two biggest airlines, Lufthansa and Air Berlin, blasted German authorities for basing their decisions on computer simulations made by Britain's Volcanic Ash Advisory Centre.
With costs mounting, German airlines vented their fury, with Lufthansa chief executive Wolfgang Mayrhuber saying the data on which the shutdowns were based "cannot be taken seriously."
"We have local knowledge, we have carried out test flights, and we are seeing that they do not correspond at all to what is being forecast out of England," Mayrhuber said on ZDF public television late on Sunday.
"No one wants to fly into a volcanic ash cloud but what we have seen in the last three days is completely different from something posing a danger."
But Ramsauer said the airline industry had “always known” what the international regulations would be in such an emergency situation.
He defended the use of the British centre's weather modelling computer system, saying it incorporated weather data provided by German authorities. It had “clearly been demonstrated” that there was volcanic ash in Germany on Sunday, he said.
German aviation safety office DFS spokesman Axel Raab told broadcaster ZDF that he understood criticism from the airline industry and that he sympathised with stranded passengers, but said the office was first and foremost responsible for safety.
“At the moment, we cannot proceed any other way,” he said.
Lufthansa, Europe's biggest airline in terms of passenger numbers, saw shares plunge by almost five percent in early morning trade before recovering slightly.
Germany's second-largest airline, Air Berlin, which has also questioned the shutdown, saw its stock drop around five percent.
German tourism giant TUI said in a statement it had already lost €23 million due to the ash cloud and that each day without flights was costing it between €5 million and €7 million more.
Airport association ADV said its members were losing more than €10 million a day in lost revenue.
Officials were also counting the cost to the wider German economy, Europe's largest.
Volker Treier, chief economist at the German Chambers of Commerce (DIHK), estimated the damage to the economy at around €1 billion per day.
Economy Minister Rainer Bruederle acknowledged that the crisis was affecting the economy "to a significant degree" and called an emergency meeting to discuss "how to avoid the worst effects."
But authorities ruled out public aid to the aviation sector, which was already struggling before this crisis, and stressed that safety remained the overriding concern.
DFS spokeswoman Kristina Kelek told German radio that "safety in this type of situation is the highest priority. And we simply do not want to take any risks in German airspace at the moment."
Transport Minister Ramsauer said it would be "cynical" to put airline profits before passenger safety and dismissed the idea that the government could intervene to prop up the industry.
"I am against any help from the state," Ramsauer told Deutschlandfunk radio, adding that an estimate of the total cost for the sector was not yet possible.
The International Air Transport Association has estimated the crisis could cost the industry as much as €150 million per day in lost revenue.
Meanwhile, scientists from the German Aerospace Centre were preparing a mission to measure the extent of the ash cloud over Germany.
As travellers were stranded across the country, Germany's train service was doing its best to pick up the strain but overcrowding was rife amid chaotic scenes as passengers fought for space.
A spokesman for Deutsche Bahn said they were pressing every train they had into service and had mobilised emergency staff reserves.