This application is developed by Keita Kitagawa, Takuya Kazusa, Youichi Handa, and relates to the estimation of drowsiness. There are various factors responsible for the drowsiness of a user such as a driver. The present invention aims to accurately determine a user’s drowsiness condition. The device contains a camera that takes an image of a user and a room environment information sensor that senses room environment information relating to an environment of a room in which a user is present. The device then estimates a drowsiness condition of a user based on the image taken by the camera and the room environment information.