It's a programmable temperature controller (hot or cold) to which thermocouple sensors can be attached. Widely used in light industry (also by hobbyists), in chemical manufacture, in furnaces for metallurgy or ceramic production, ovens or refrigeration equipment for food & beverage manufacture, incubators and such.
If there's a model number on it, then it may have a specific intended application rather than being multi-purpose. Produced by MYPIN in China.