NOVELTY - A metal-carbene complex (I) is new.    USE - Metal-carbene complex is used for organic electronic device e.g. organic light-emitting diodes, organic photovoltaic cells, organic field-effect transistors and light-emitting electrochemical cells, apparatus e.g. stationary visual display units e.g. visual display units of computers, televisions, visual display units in printers, kitchen appliances and advertising panels, illuminations, information panels, and mobile visual display units e.g. visual display units in cellphones, tablet personal computers, laptops, digital cameras, MPEG audio layer-3 player, vehicles and destination displays in buses and trains, illumination units, keyboards, clothing, furniture and wallpaper, electrophotographic photoreceptors, photoelectric converters, organic solar cells, switching elements, organic light emitting field effect transistors, image sensors, dye lasers and electroluminescent devices (all claimed). Uses include but are not limited to emitter, hole transport material, charge transport material, matrix material and charge blocker.    ADVANTAGE - The organic electronic device using the metal-carbene complex has high efficiency, stability and charge carrier mobility, and film-forming property.    DETAILED DESCRIPTION - A metal-carbene complex of formula (I) is new.    M=Pd or Pt;    R1=linear or branched alkyl radical optionally containing at least one functional group having 1-20 carbon atoms, or cycloalkyl optionally containing at least one functional group having 3-20 carbon atoms, aryl optionally containing at least one functional group having 6-30 carbon atoms or heteroaryl optionally containing at least one functional group having 5-18 carbon atoms (all optionally substituted and optionally interrupted by at least one heteroatom);    R2,R2'=linear or branched 1-6C alkyl, or 3-20C cycloalkyl, 6-20C aryl or 5-18C heteroaryl (all optionally substituted);    R3=H, linear or branched 1-6C alkyl, or optionally substituted 6-20C aryl;    R4,R5=H, linear or branched alkyl and optionally containing at least one functional group having 1-6 carbon atoms, or cycloalkyl optionally containing at least one functional group having 3-12 carbon atoms, aryl optionally containing at least one functional group having 6-15 carbon atoms, heteroaryl optionally containing at least one functional group having 5-18 carbon atoms (all optionally substituted and optionally interrupted by at least one heteroatom), or group having donor or acceptor property;    A=CR6 or N, in which at least 3 or more of A is R6;and    R6=H, linear or branched alkyl optionally interrupted by at least one heteroatom and optionally containing at least one functional group having 1-20 carbon atoms, or cycloalkyl optionally interrupted by at least one heteroatom and optionally containing at least one functional group having 3-20 carbon atoms, aryl optionally interrupted by at least one heteroatom and optionally containing at least one functional group having 6-30 carbon atoms, heteroaryl optionally interrupted by at least one heteroatom and optionally containing at least one functional group having 5-18 carbon atoms and/or heteroatoms (all optionally substituted), or group having donor or acceptor property.    INDEPENDENT CLAIMS are included for the following:    (1) organic electronic device, which contains metal-carbene complex (I);    (2) light-emitting layer, which contains metal-carbene complex (I);    (3) usage of metal-carbene complex; and    (4) preparation of metal-carbene complexes.