Disclosed are substance detection and identification devices, and methods of using them for detection and identification of substances in ambient surroundings, on surfaces of objects, inside closed items or in fluids. A substance detection and identification device may comprise a housing, an opening in the housing for passage of sample material therethrough, a sensing unit located in the housing and an array of sensing elements configured and operable to interact with sample material in the vicinity thereof for detecting one or more specific substances and generating sensing data indicative thereof. A sample path defined in the housing between the opening and the sensing unit is used for facilitating flow of the sample material towards the sensing unit. A gas inlet assembly provided in the housing is configured for providing a predetermined supply of the sample material to the sensing elements in the sensors array, to thereby enable a predetermined time pattern of the sensing data from the array of sensing elements. A heating unit may be provided in the housing for heating the sensing elements.