NOVELTY - A polysiloxane compound (I) is new.    USE - New polysiloxane compound used for manufacture of thin film for manufacturing microstructure (all claimed) for manufacturing high-density recording media, high integration electronic component, and substrate of solar cell.    ADVANTAGE - The micro-patterns of the thin film comprising the polysiloxane compound is manufactured by simple process.    DETAILED DESCRIPTION - A polysiloxane compound of formula (I) is new.    R1=aryl or arylalkyl (both optionally substituted), in which one or more hydrogen of benzene ring is optionally substituted by halo or 1-10C alkyl optionally substituted by fluoro (one or more -CH2- of 1-10C alkyl does not adjoin which is optionally substituted by -O- or phenylene), in which alkylene of arylalkyl is 1-10C alkylene (one or more hydrogen optionally substituted by fluoro, and one or more -CH2- does not adjoin optionally substituted by -O- or phenylene);    n=1-10;    R2=1-10C alkyl, or optionally substituted aryl;    Y'=substituent of formula (i), 11-30C alkyl, or polyoxyalkylene having number average molecular weight of 3000 or less;    R3=1-20C alkylene, in which one or more -CH2- is optionally substituted by -O-, -C(=O)- or phenylene;    R4=1-30C alkyl, in which one or more non-adjacent -CH2- is optionally substituted by -O-;and    m=1-5.    INDEPENDENT CLAIMS are included for the following:    (1) manufacture of thin film, which involves forming composition layer on to-be-processed component by coating the polysiloxane compound (I), in which composition containing solvent is dissolved on to-be-processed component, heat-processing the resultant product at specified temperature which expresses self-organization of the polysiloxane compound, and forming micro-patterns; and    (2) manufacture of microstructure, which involves forming the thin film containing the polysiloxane compound on substrate, and removing side chain portion or arylsiloxane portion of the polysiloxane compound in thin film.