NOVELTY - Formation of pattern involves forming coating film by applying photocurable nanoimprint composition on substrate, drying, contacting pattern-formation surface and coating film of metal mold, irradiating using light and hardening coating film, and forming pattern corresponding to pattern which separates metal mold from cured coating film. The photocurable nanoimprint composition comprises hydrolysis mixture (A) comprising hydrolyzate of (meth)acryl group-containing organosilicon compound (A) (I) or (II), polymerizable monomer (B) having (meth)acryl group and photoinitiator (C).    USE - Formation of pattern used as mask in manufacture of surface-treated substrate (claimed). Uses include but are not limited to LED board, secondary battery, solar cell, fuel cell, and in biotechnology field.    ADVANTAGE - The method efficiently forms pattern with excellent etching tolerance with respect to chlorine gas.    DETAILED DESCRIPTION - Formation of pattern involves forming a coating film by applying a photocurable nanoimprint composition on a substrate, drying at 150-250 degrees C, contacting a pattern-formation surface and coating film of metal mold, irradiating using light and hardening the coating film, and forming pattern corresponding to the pattern which separates the metal mold from the cured coating film. The photocurable nanoimprint composition comprises hydrolysis mixture (A) comprising hydrolyzate of (meth)acryl group-containing organosilicon compound (A) of formula (I) or (II), polymerizable monomer (B) which has (meth)acryl group and photoinitiator (C).    R1=H or methyl;    R2=1-20C alkylenyl or 3-10C cycloalkylenyl;    R3=1-4C alkyl, 3-4C cycloalkyl, or 6-12C aryl;    R4=1-4C alkyl or 3-4C cycloalkyl;    l=1-3;    m=0-2;    k=1-3;    l+m+k=4;    M=tungsten, zirconium, tin, indium, antimony, molybdenum, niobium or hafnium;and    R5=1-10C alkyl.    (i) When M is tungsten, p is 6 or 5; (ii) When M is molybdenum and niobium, p is 5; (iii) When M is zirconium, tin or hafnium, p is 4; and (iv) When M is indium or antimony, p is 3. An INDEPENDENT CLAIM is included for manufacture of surface-treated substrate, which involves dry-etching substrate surface with etching gas by using pattern as mask.