A headup display device includes: a display having an emission surface that emits display light relating to predetermined information; a reflecting member that is disposed above the display and reflects the display light emitted from the display; a combiner part on which the display light reflected off the reflecting member is incident; a transmissive member that is disposed between the display and the reflecting member to cover the emission surface and transmits the display light emitted from the display toward the reflecting member; and a blocking member that is disposed above the transmissive member and blocks out light that is reflected off the transmissive member to be incident on the combiner part. A transmissive-member-side end of the blocking member is disposed to be movable from a first position where the light is blocked out to a second position closer to the transmissive member than the first position is.