Eiffel's Diary  is a diary kept by Monsieur Eiffel.
Although most of its contents are unknown, it is known Monsieur Eiffel kept his theories on ectoplasmic entrapment and information about his control box and its connection to the Eiffel Tower in the diary. The diary was then kept in a desk drawer in a the pavilion atop the tower. About 100 years later, Egon Spengler found the diary and quickly studied it in order to deal with The Ghosts of France.
- ↑ Egon Spengler (2009). The Real Ghostbusters - "The Ghostbusters in Paris" (1987) (DVD ts. 11:41-11:43). Time Life Entertainment. Egon says: "This is it. This is Eiffel's diary."