Seat, in particular child seat for a motor vehicle

A seat for a motor vehicle for being removably attached to a vehicle seat firmly connected to the vehicle body comprises a base firmly connectable to the motor vehicle body, a seat shell optionally removable from the base, and an installation device with at least one coupling location for removably attaching the base at the motor vehicle body and/or for removably attaching the seat shell at the base, wherein the installation device comprises a locking seat and an engagement member assigned to the locking seat for the at least one coupling location, respectively, preferably for several, in particular for all coupling locations, wherein in a mounting position of the base and/or the seat shell the engagement member and the locking seat are in locking engagement with each other. The seat has an electronic monitoring device with an optical sensor for the at least one coupling location, preferably for each coupling location, which optical sensor verifies whether the engagement member and the assigned locking seat are in the operational locking engagement.