I need an answer to this riddle! (my sister asked me, and now she says I can ask online)?

There is a square-shaped room. It has 4 walls, a ceiling, and a floor, all made of indestructible material. There are no stairs, elevators, or escalators; in fact, there is no electricity or plumbing. There are no windows or doors, and no trapdoors, nor are there any cracks in the walls, ceiling, or floor. There are no stairs and no chimney. A man is inside this room, and he is bare naked, and has nothing with him, yet he is easily able to leave the room without help. How?