The invention relates to an improved cranial device with a rotary inclination detector, including a container box which can be secured to the cranium of sleeping person and which contains an electric motor and an eccentric counterweight coupled thereto, forming a vibrator. The device also includes a battery or a battery holder for at least one battery, which is provided with two axially opposed projecting contacts or studs. The container box is provided with inclined formations with dielectric properties, on which the battery or battery holder can roll by means of the studs thereof, and two electric contacts on which the inclined formations terminate, such that, when the battery holder is placed on the electric contacts, the motor circuit is closed, thereby activating the vibrator.