A head mounted display device comprising: a helmet to be mounted on a head of a user; a visor connected to the helmet, the visor having a curved surface protruding outward and configured to be placed in front of eyes (EL, ER) of the user; a display section (11, 11A, 11B, 11C, 11L, 11R) for creating a display image; and a projection optical system (12, 12L, 12R) for projecting display light onto a reflecting surface of the visor, the display light containing, as a piece of information, the display image created by the display section, the head mounted display device configured to create a virtual image originating from the display image within a view of an external scene that is visible through the visor, wherein: an intermediate image is formed within the projection optical system or on an optical path between the projection optical system and the reflecting surface; the visor is rotatable with respect to the helmet about an axis parallel to an X axis and is slidable upward to allow the user to put the helmet on or remove the helmet, while an upper portion of the reflecting surface is held in an inclined position tilting outward in front of the eyes of the user when the visor is in use; and the reflecting surface of the visor has an aspherical shape whose curvature in a Y'-Z' plane is smaller than the curvature in an X'-Z' plane, where: a central position between the right and left eyes of the user facing horizontally frontward is defined as an origin O; an axis extending frontward from the origin O as viewed from the user is defined as the Z axis; an axis orthogonal to the Z axis and directed upward as viewed from the user is defined as the Y axis; an axis orthogonal to both the Z axis and the Y axis is defined as the X axis; a point at which an optical axis of a light beam incident on the reflecting surface of the visor intersects with the reflecting surface is defined as an intersection point O'; a normal to the reflecting surface at the intersection point O' is defined as the Z' axis; an axis which is orthogonal to the Z' axis and forms, with the Z' axis, a plane containing the optical axis of the incident light beam and an optical axis of an outgoing light beam resulting from the incident light beam reflected by the reflecting surface and travelling toward an eye of the user, is defined as the Y' axis; and an axis orthogonal to both the Y' axis and the Z' axis is defined as the X' axis. an intermediate image is formed within the projection optical system or on an optical path between the projection optical system and the reflecting surface; the visor is rotatable with respect to the helmet about an axis parallel to an X axis and is slidable upward to allow the user to put the helmet on or remove the helmet, while an upper portion of the reflecting surface is held in an inclined position tilting outward in front of the eyes of the user when the visor is in use; and the reflecting surface of the visor has an aspherical shape whose curvature in a Y'-Z' plane is smaller than the curvature in an X'-Z' plane, where: a central position between the right and left eyes of the user facing horizontally frontward is defined as an origin O; an axis extending frontward from the origin O as viewed from the user is defined as the Z axis; an axis orthogonal to the Z axis and directed upward as viewed from the user is defined as the Y axis; an axis orthogonal to both the Z axis and the Y axis is defined as the X axis; a point at which an optical axis of a light beam incident on the reflecting surface of the visor intersects with the reflecting surface is defined as an intersection point O'; a normal to the reflecting surface at the intersection point O' is defined as the Z' axis; an axis which is orthogonal to the Z' axis and forms, with the Z' axis, a plane containing the optical axis of the incident light beam and an optical axis of an outgoing light beam resulting from the incident light beam reflected by the reflecting surface and travelling toward an eye of the user, is defined as the Y' axis; and an axis orthogonal to both the Y' axis and the Z' axis is defined as the X' axis.