A humidifier, including: a flat humidification member formed of a water absorbing member and arranged in an upright posture; a nozzle serving as a water supply unit configured to supply water to the humidification member; and an airflow direction changing plate arranged with a clearance secured between the airflow direction changing plate and the humidification member. On a flat surface of the airflow direction changing plate opposed to the flat humidification member, an airflow direction changing portion is arranged to project toward the flat humidification member, the airflow direction changing portion being configured to change a direction of an air current flowing between the flat humidification member and the airflow direction changing plate.