NOVELTY - A polymer having spiro ring-containing repeating unit (I), is new.    USE - New polymer used as semiconducting material, charge transport material, electrically conducting material, photoconducting or light emitting material in optical, electrooptical, electronic, electroluminescent or photoluminescent components or devices e.g. organic field effect transistors (OFET), thin film transistors (TFT), integrated circuits (IC), logic circuits, capacitors, radio frequency identification (RFID) tags, devices or components, organic light emitting diodes (OLED), organic light emitting transistors (OLET), flat panel displays, backlights of displays, organic photovoltaic devices (OPV), solar cells, laser diodes, photoconductors, photodetectors, electrophotographic devices, electrophotographic recording devices, organic memory devices, sensor devices, charge injection layers, charge transport layers or interlayers in polymer light emitting diodes (PLEDs), Schottky diodes, planarizing layers, antistatic films, polymer electrolyte membranes (PEM), conducting substrates, conducting patterns, electrode materials in batteries, alignment layers, biosensors, biochips, security markings, security devices, and components or devices for detecting and discriminating DNA sequences (all claimed).    ADVANTAGE - The polymer has excellent charge carrier mobility, high thermal, mechanical and chemical stability.    DETAILED DESCRIPTION - A polymer having spiro ring-containing repeating unit of formula (I), is new.X,Y'=S or O.    INDEPENDENT CLAIMS are included for the following:    (1) monomer of formula: R2-Ar1-U'-Ar2-R3;    (2) manufacture of the polymer;    (3) mixture or blend comprising polymer(s) having semiconducting, charge transport, hole/electron transport, hole/electron blocking, electrically conducting, photoconducting or light emitting properties;    (4) formulation, which comprises the polymer, solvent(s), preferably selected from organic solvents; and    (5) use of polymer, mixture, blend or formulation semiconducting material, charge transport material, electrically conducting material, photoconducting or light emitting material in optical, electrooptical, electronic, electroluminescent or photoluminescent components or devices.    U'=unit of formula (I);    Ar1-Ar3=aryl or 5-30C heteroaryl optionally substituted by R1;    R1=F, Br, Cl, -CN, -NC, -NCO, -NCS, -OCN, -SCN, -C(O)NR'R", -C(O)X', -C(O)R', -NH2, -NR'R", -SH, -SR', -SO3H, -SO2R', -OH, -NO2, -CF3, -SF5, optionally substituted silyl, carbyl or 1-40C hydrocarbyl optionally containing hetero atoms, or P'-Sp-;    R',R"=H or optionally substituted 1-40C carbyl or hydrocarbyl;    P'=polymerizable or crosslinkable group;    Sp=spacer group or single bond;    R2,R3=F, Br, Cl, H, -CH2Cl, -CHO, -CH=CH2, -SiRa'Ra"Ra"', -SnRa"Ra'", -BRa'Ra", -B(ORa')(ORa"), -B(OH)2, or P'-Sp;    Ra',Ra",Ra'"=R';and    or two of Ra',Ra" and Ra'"=ring containing hetero atom.