A vehicle-mounted imaging device comprising: an accretion diagnosis unit that diagnoses a state of contamination which has been accreted on a lens of a camera that is mounted on an outside of a vehicle, or on a protective member of the lens; and an external communication unit that is configured to communicate in use with a display device and/or a speaker device provided in the vehicle and with a navigation device having a vehicle position identifying unit which identifies a position of the vehicle and a database containing a map and peripheral facility information; a contamination notification determination unit that determines a presence or absence of a notification of contamination, based on positional information on a predetermined type of facility that is a previously determined facility which is obtained from the navigation device through the external communication unit, and in which the contamination can be eliminated, and on the vehicle, wherein when it has been determined by the accretion diagnosis unit that a contamination level of the lens of the camera or the protective member of the lens is a predetermined value or higher, and it has been determined by the contamination notification determination unit that the predetermined type of facility exists in a predetermined distance range from the vehicle, from a present position identified by the vehicle position identifying unit and information in the database, the vehicle-mounted imaging device notifies a user that the lens of the camera or the protective member of the lens is contaminated, and also displays a candidate of the predetermined type of facility, by the display device and/or the speaker device provided in the vehicle. an accretion diagnosis unit that diagnoses a state of contamination which has been accreted on a lens of a camera that is mounted on an outside of a vehicle, or on a protective member of the lens; and an external communication unit that is configured to communicate in use with a display device and/or a speaker device provided in the vehicle and with a navigation device having a vehicle position identifying unit which identifies a position of the vehicle and a database containing a map and peripheral facility information; a contamination notification determination unit that determines a presence or absence of a notification of contamination, based on positional information on a predetermined type of facility that is a previously determined facility which is obtained from the navigation device through the external communication unit, and in which the contamination can be eliminated, and on the vehicle, wherein when it has been determined by the accretion diagnosis unit that a contamination level of the lens of the camera or the protective member of the lens is a predetermined value or higher, and it has been determined by the contamination notification determination unit that the predetermined type of facility exists in a predetermined distance range from the vehicle, from a present position identified by the vehicle position identifying unit and information in the database, the vehicle-mounted imaging device notifies a user that the lens of the camera or the protective member of the lens is contaminated, and also displays a candidate of the predetermined type of facility, by the display device and/or the speaker device provided in the vehicle.