A substrate for future atomic chain electronics, where adatoms are placed at designated positions and form;atomically precise device components, is studied theoretically. The substrate has to serve as a two-dimensional template for adatom mounting with a reasonable confinement barrier and also provide electronic isolation, preventing unwanted coupling between independent adatom chains. For excellent structural stability, we demand chemical bonding between the adatoms and substrate atoms to secure the positions (chemical bonding scheme), but then good electronic isolation is not always guaranteed and necessary conditions are clarified. The substrate influences fundamental chain properties through chemical bonds. A chain with group IV adatoms having two chemical bonds each, or a chain with group III adatoms having one chemical bond each, is semiconducting. Charge transfer from or to the substrate across the chemical bonds brings about unintentional doping for semiconducting chains. The electronic properties have to be considered for the combination of the adatom and substrate systems in this scheme, even though the adatom modes are well localized in the adatom chains.