An electronic device may include: a housing; a flexible display which can be slid out from an inner space of the housing; and a processor, wherein the processor is configured to: control a first screen operation on the flexible display having a first size; determine whether the flexible display is slid out; control a second screen operation on the flexible display having a second size when the flexible display is slid out; and control the second screen operation such that a first page displayed during the first screen operation and at least some of icons included on a second page are displayed, and a user interface is displayed to allow the at least some of icons included on the second page to be distinguished from the first page.