Optical smoke detector comprising: - an optical detection chamber ; - at least one light source configured to emit a beam of light into said optical chamber ; - a first detection unit comprising at least one photoelectric detector - hereinafter "first photodetector" - free from all direct illumination by the light source or sources ; - a second detection unit comprising at least one photoelectric detector - hereinafter "second photodetector" - , wherein said second unit is configured such that the second photodetector directly receives the light emitted by at least one of said light sources , hereinafter referred to as "first light source" ; - a control unit for monitoring the aging of the optical smoke detector , configured for controlling/managing the first light source such that it temporarily emits a beam of light, wherein said control unit is also configured to receive, in response to the emission of said beam of light emitted by the first light source , a first signal (S1) issued by the second photodetector , and to detect on the basis of said first signal (S1) and at least one second signal (S2) generated by one of the photodetectors of the optical detector a presence of dust particles in the optical chamber and/or an aging of the first light source ; wherein the optical detector according to the invention is characterised in that the control unit is configured to calculate a first difference and a second difference, wherein the first difference is the difference between a value obtained for said first signal (S1) on the basis of a measurement of the latter by the control unit and a first reference value, and the second difference is the difference between a value obtained for said second signal (S2) on the basis of a measurement of the latter by the control unit and a second reference value, and to detect said presence of dust particles in the optical chamber and/or said aging of the first light source on the basis of said differences. - an optical detection chamber ; - at least one light source configured to emit a beam of light into said optical chamber ; - a first detection unit comprising at least one photoelectric detector - hereinafter "first photodetector" - free from all direct illumination by the light source or sources ; - a second detection unit comprising at least one photoelectric detector - hereinafter "second photodetector" - , wherein said second unit is configured such that the second photodetector directly receives the light emitted by at least one of said light sources , hereinafter referred to as "first light source" ; - a control unit for monitoring the aging of the optical smoke detector , configured for controlling/managing the first light source such that it temporarily emits a beam of light, wherein said control unit is also configured to receive, in response to the emission of said beam of light emitted by the first light source , a first signal (S1) issued by the second photodetector , and to detect on the basis of said first signal (S1) and at least one second signal (S2) generated by one of the photodetectors of the optical detector a presence of dust particles in the optical chamber and/or an aging of the first light source ; <EOS>