The e-visa website states the following;
"Financial evidence showing monthly income of no less than 40,000 THB or having the current balance of 400,000 THB, e.g. bank statements, proof of earnings"
Individual embassies can have their own rules but it's not going to be much different. You could probably use an equivalent amount in your home country, you certainly could do so if applying in the UK, USA, etc.