Any foreigners who want to work in Thailand can apply for a business visa at the Thai Embassy Abroad to obtain Non-Immigrant Visa (Non-B), which can live for 3 months or if the foreigner arrivals in Thailand is not a Non-B visa you can alter to be Non-B visa as it can be done at the Immigration Bureaus. (Please refer alter the type of visa ).
Conditions for make visa and work permit in Thailand. The step to application the visa is 1 year. Foreigners have to get Non-Immigrant B visa, and then when foreigners arrival to Thailand.