NOVELTY - A biscarbazole derivative (IA or IB), is new.    USE - New biscarbazole derivative is used for host material of organic electroluminescent elements (both claimed). Can also be used for organic solar cells, organic semiconductor lasers, sensors, organic thin film transistors, and other organic electronic devices.    ADVANTAGE - The new biscarbazole derivative provides organic electroluminescent elements having excellent durability and luminous efficiency, and low drive voltage. Power consumption is reduced.    DETAILED DESCRIPTION - A biscarbazole derivative of formula (IA or IB), is new.    A1=optionally substituted nitrogen-containing heterocyclic ring group with 1-30 ring-forming carbon atoms;    A2=aryl with 6-30 ring-forming carbon atoms or nitrogen-containing heterocyclyl with 1-30 ring-forming carbon atoms (both optionally substituted);    X1,X2=coupling group, single bond, or aryl with 6-30 ring-forming carbon atoms, condensed aryl with 6-30 ring-forming carbon atoms, heteroaryl with 2-30 ring-forming carbon atoms, or condensed heteroaryl with 2-30 ring-forming carbon atoms (all optionally substituted);    Y1-Y4=H, fluoro, cyano, or 1-20C (halo)alkyl, 1-20C (halo)alkoxy, 1-10C alkylsilyl, 6-30C arylsilyl, aryl with 6-30 ring-forming carbon atoms, condensed aryl with 6-30 ring-forming carbon atoms, heteroaryl with 2-30 ring-forming carbon atoms, or condensed heteroaryl with 2-30 ring-forming carbon atoms (all optionally substituted);    adjacent Y1-Y4=ring structure;    p,q=1-4;and    r,s=1-3.    An INDEPENDENT CLAIM is included for organic electroluminescent element (1) consisting of organic thin-film layers (10) comprising a light-emitting layer provided between a cathode (4) and an anode (3). The organic electroluminescent element material containing compound (IA or IB) is included in the organic thin-film layers.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the organic electroluminescent element. (Drawing includes non-English language text)    Organic electroluminescent element (1)    Substrate (2)    Anode (3)    Cathode (4)    Electron injection layer (7)    Organic thin film layer (10)