Abstract: A diaper has a flexible laminar body configured to a body of a baby and, in a central portion of a face thereof which is in contact with the baby's body, an area of wetness-absorbent material is provided. Attachments are arranged at ends of the laminar body for placing, attaching and removing of the diaper from the baby's body. In the central portion, humidity, thermal and electrochemical sensors are provided so that the thermal and electrochemical sensors sense the temperature and chemical analyses of the baby's urine. The sensors constitute an emitter that sends a signal to the receiver for emitting an acoustic and/or luminous signal.