A medium storage cassette includes a medium storage portion that stores a medium; and a medium support tray that is provided in the medium storage portion such that the medium support tray can be displaced with respect to the medium storage portion in a slidable manner, the medium support tray being able to be set in a contained state that is a state in which the medium support tray is slid to an upper portion of the medium storage portion and being able to be set in an extended state that is a state in which a medium supporting surface that supports the medium becomes an inclined surface that is oriented obliquely upwards towards an end portion of the medium support tray and in which the medium supporting surface is extended outside of the medium storage portion.