A determination device includes an receiver that receives a face image of a user from a camera whose direction of optical axis is predetermined with respect to a reference direction and a determiner that determines the face direction of the user depending on whether or not the reliability of a face direction calculated based on the face image and a learning model. The determiner determines the face direction depending on whether or not the reliability is greater than a first threshold value if the optical axis of the camera faces in a first direction and determines the face direction depending on whether or not the reliability is greater than a second threshold value different from the first threshold value if the optical axis faces in a second direction different from the first direction.