To provide a sleep inducing device capable of inducing a user to a comfortable sleep using Schumann waves with frequency of 7.8 Hz (further precisely, 7.83 Hz) which is continuously present between the earth ground and the ionosphere, and is well known as inaudible sound for human ears while affecting the human brain waves.

This sleep inducing device is configured to generate pulse sound with audio frequency of, for example, around 100 Hz at a constant period for every 1 cycle of Schumann wave. When a person sleeps actually hearing the constant-period pulse sound generated by this sleep inducing device 1, or, the constant-pulse and monotonous sound ticked down for every cycle of Schumann wave, the person can have the easy falling-in-asleep effect.