What is the maximum amount per transaction in Baht that You can get out of an ATM in Thailand?

Depends is the Atm card from a Thai bank or a foreigner bank. I believe it's 20,000 baht per transaction from a foreigner bank. If a foreigner bank it seems some banks only let you take 10,000 while some others will give you no more than 20,000 baht. I always use Krung Thai bank because their machines always let you take 20,000 baht.