Abstract: Burglar alarm apparatus particularly for motor-cars or the like, comprising an electronic memory with digital combination, associated with a microcomputer for controlling all the functions of the apparatus with no need to manually control its enabled or disabled operation modes, which automatically take place when the combination valid for operation has been entered.The opportunity of starting the engine by means of the ignition key, with the valid combination entered, is also provided for, in order to permit the parking manoeuvres, still keeping on the function of automatically enabling the apparatus when the engine is stopped.