PURPOSE: To detect and warn that a human body sticks out of bedding by providing the bedding on which a plurality of sensors are disposed and a monitor means.

CONSTITUTION: Bedding 1, such as a mattress, a blanket and a sheet, and a monitor means 2 for detecting and reporting conditions of a sleeper on the bedding 1 are connected together in such a manner that intercommunication is made possible. A plurality of sensors M1, M2,..., MN are disposed on the bedding 1 which makes contact with the human body from the upper or lower portion thereof when the user is asleep. The sensors M1, M2,..., MN are regularly arranged crosswise and lengthwise, for example, so as to detect the position of the body of the sleeper, etc., and when the monitor means 2 receives signals output from the sensors M1, M2... MN and recognizes the body as sticking out, an alarm sound is produced by alarm means. Therefore it is made possible to prevent the body of the sleeper from sticking out of the bedding 1 for a long time.