To prevent accidents like deviation from a course occurring in a skiing area.

A danger monitor system comprises; an entrance read means which is provided at a lift entrance in a skiing area and reads data stored in information recording mediums (IC cards) which skiers have; an exit read means which is provided at a lift exit in the skiing area and reads data stored in information recording mediums which skiers have; and a determination means which determines the occurrence of abnormality on a skier in the case that prescribed data specifying the skier, which is read at the lift entrance in the skiing area, is not read at the lift exit in the skiing area within a prescribed time.