To reduce the labor and cost for maintenance and management of replacement of a panel and cleaning of a window of a fire hydrant door by reducing dirt in the panel of the apparatus.

In the tunnel fire-extinguisher apparatus 10, a fire extinguisher is stored in a casing 12 having a fire-extinguisher door 28. A triangular fin 70 for biasing the air current A from sideways in the direction B to separate from the door surface is disposed in the vertical direction on the door surface of the fire-extinguisher door 28 located on the upstream side in the direction of advancement of vehicles inside a tunnel. The fire-extinguisher door 28 has a translucent panel through which the interior is visible, and the triangular fin 70 is disposed sideways according to the height of the translucent panel.