A sleeping box for installation in an aircraft includes a casing which is suitable for accommodating a person located in a reclining position parallel to a longitudinal axis of the casing and which has an access aperture in the area of a front side which extends perpendicularly to the longitudinal axis of the casing. The sleeping box also includes a fastening apparatus which is configured to fasten the sleeping box within a passenger cabin of the aircraft in such a way that the longitudinal axis of the casing extends perpendicularly to a longitudinal axis of the passenger cabin and the access aperture of the casing borders on an aisle which is present within the passenger cabin.