The direct creation of an electron-positron pair by a high-energy charged particle manifests itself in a certain type of track configuration which is known as a 'trident'. A device for automatic scanning and detection of 'tridents' in nuclear emulsion is described. The device consists of two main parts: a TV camera which analyses the magnified image of the emulsion and a logical detection unit which counts all the observed tracks and also counts the track configurations which may correspond to 'tridents'. The performance of the apparatus is discussed.