To provide an alarm device for a vehicle capable of installing a speaker by suppressing a size increase in the device.

In an alarm device 1 for a vehicle including an indicator 2 for outputting visual information to be projected on a member 7 to be projected to be visually observed by a visual observer 101, auditory information output means 8 for outputting auditory information, and a housing 5 housing the indicator 2 and the auditory information output means 8 and provided with a housing opening part 6 for emitting the visual information, the housing opening part 6 is trapezoidal and continuously expands from the visual observer 101 side toward the member 7 to be projected, and a wall part 61 constituting the housing opening part 6 is provided with the auditory information output means 8.