To provide a room mirror device enabling a driver to safely confirm information while reducing a sight line movement, and enabling all the occupants (including the driver) to accurately confirm the information, on useful information for driving and getting in an automobile.

A room mirror device includes a case body constituted of a rear case 11 and a front case 18, a convex curved surface mirror 19 installed on the front side of the front case 18, and a display panel 14 stored in the case body. A window part 19a capable of visually confirming the inside from the outside, is arranged in a partial area of the curved surface mirror, and the display panel 14 is arranged so as to run along the curved surface mirror (to become substantially parallel to a contact plane of a curved surface) on the reverse surface side of the window part.