A flexible apparatus is provided. The flexible apparatus includes: a screen generator configured to generate a user interface (UI) screen; a plurality of sensors configured to sense deformation of the flexible apparatus and output a result of sensing; a storage configured to store a crumple determining condition with regard to crumpling of the flexible apparatus; and a controller configured to determine whether the result of the sensing by the plurality of sensors satisfies the crumple determining condition stored in the storage, and in response to determining that the crumple determining condition is satisfied, perform an operation corresponding to the crumple determining condition.