It is an object of the present invention, in the case of an apparatus in which a liquid containing matter having a lower boiling point than the liquid is made to flow down along external surfaces of guides, during which time the low boiling point matter is evaporated, to provide a specific apparatus that can be operated stably for a prolonged period of time on an industrial scale such that not less than 1 ton/hr of the liquid is produced through the evaporation, and furthermore to provide a specific industrial evaporation apparatus according to which there are no problems due to degeneration caused by some of the liquid residing in the apparatus for a prolonged period of time. The present inventors arrived at the present invention upon discovering that the above object can be attained, and a high-quality and high-purity concentrated liquid or condensation polymer or thermoplastic polymer can easily be obtained, by using an industrial continuous evaporation apparatus having a specified structure in which there are guides that do not themselves have a heat source, a flow path controlling member having a function of making the liquid fed onto a perforated plate from a liquid receiving port flow mainly from a peripheral portion toward a central portion of the perforated plate is installed in a liquid feeding zone, the perforated plate and the holes therein satisfy specified relationships (formulae (6) and (7)), and formulae (1) to (5), preferably formulae (1) to (13), or preferably formulae (1) to (15), are satisfied.