The present invention relates to a greenhouse having automatic control variability according to internal and external environmental conditions and a method for managing same. Breaking from conventional greenhouse frame structures, the present invention provides a greenhouse having a volume variable structure so that the skeleton frame of the greenhouse can actively cope with changes in external conditions, thus preventing the greenhouse from damage caused by adverse climatic conditions. Also, the opening and closing of ceiling windows and side windows can be accurately controlled when opening or closing the windows in response to changes in wind speed and the temperature inside and outside the greenhouse, and thus the indoor and outdoor temperature can be easily regulated to constantly maintain optimal growth conditions. The growth efficiency is simulated with respect to changes in growth conditions according to volume variations and changes in the temperature inside the greenhouse when the ceiling windows and side windows are open or closed, and the results thereof are delivered to an operator of the greenhouse. Data values acquired in this manner are accumulated, thus making it possible to optimally adjust the environmental conditions.