Different Embassy's ask for different requirements that can range from 1 month bank statements to 6 months, most now are ask for 500k funds shown in a bank account and also proof of income salary, wage slips , to support yourself while in Thailand, if you are unemployed I would recommend showing excess funds not only 500k but enough to support your living costs monthly upto 180 days, Soft power DTV you don't have to be employed but Embassy's are getting more strict