The book is narrated in the first person by a character also named Cyrano.
Cyrano attempts to reach the Moon to prove there is a civilization that sees the Earth as its own moon. He launches himself into the sky from Paris by strapping bottles of dew to his body, but lands back on Earth. Believing he had traveled straight up and down, he is confused by local soldiers who tell him he is not in France; they escort him to the provincial governor who informs him that it is in fact New France. The narrator explains to the governor that all matter is formed inside and expelled from stars, and that once the Sun has run out of fuel it will consume the planets and restart the cycle. He uses New France as evidence for this theory, claiming that it had only recently been discovered by European explorers because the Sun had only recently sent it to Earth.
The narrator tries again to reach the Moon, this time with a flying machine that he launches off the edge of a cliff. Though the craft crashes, local soldiers attach rockets to it, hoping that it will fly to celebrate the feast day of St. John the Baptist. Dismayed at this use of his machine, the narrator attempts to dismantle it while the fuse is lit, but the machine takes off and sends him into space. He meets the Moon's inhabitants, who have four legs, musical voices, and fantastical weapons that cook game for a meal as it's shot. The Moon inhabitants give names made of musical notes. For example, the king's name was given as
The Moon inhabitants greatly prized having a large nose, "because after Thirty Ages experience we have observed, that a great Nose is the mark of a Witty, Courteous, Affable, Generous and Liberal Man; and that a little Nose is a Sign of the contrary". (The topic of the nose comes up in Cyrano de Bergerac (play)).
He also meets the ghost of Socrates and Domingo Gonsales of Francis Godwin's The Man in the Moone. His discussions with Gonsales include how God is useless as a concept, that humans cannot achieve immortality, and that they do not have souls. After these discussions, the narrator returns to Earth.