Who owns the work permit in Thailand - the employee, employer, or the Ministry of Labour?

And as we know, a Work Permit is not really a Visa related question. You have the answer. Have a good day.

And, as another thread has discussed, there is a chance you may be asked to show it when re-entering Thailand, so it should certainly be carried when travelling.

And this is a copy of the last page in the Work Permit:

It is applied for in employees name, it has the employees picture in it. It allows the employee to work at a described place and do the described job. And the employee signed the booklet when he/she picked it up at the Ministry of Labor. It is from the Employee, not from the company.