A curable composition, comprising: a polyether polymer containing a reactive silyl group represented by the following formula; and at least one of a polyether polymer containing a reactive silyl group represented by the following formula and a (meth)acrylic polymer containing a reactive silyl group represented by the following formula: -W-CH 2 -SiR 1 a R 2 b X c wherein R 1 is a methoxymethyl group; R 2 represents a C1 to C20 hydrocarbon group, a C6 to C20 aryl group, a C7 to C20 aralkyl group, or a triorganosiloxy group represented by R 0 3 SiO- wherein each of three R 0 s is a C1 to C20 hydrocarbon group and they may be the same as or different from each other; X represents a hydroxy or hydrolyzable group; W represents a linking group -O-R 8 - wherein R 8 represents a divalent C1 to C8 hydrocarbon group, a is 1 or 2, b is 0 or 1, and c is 1 or 2, provided that a+b+c = 3 is satisfied; and in the case that a plurality of R 1 s, R 2 s, or Xs exist, they may be the same as or different from each other, -V-SiR 2 d X 3-d wherein R 2 and X are defined as mentioned in formula; V represents a divalent C2 to C8 hydrocarbon group; d represents any of 0, 1, and 2; and in the case that a plurality of R 2 s or Xs exist, they may be the same as or different from each other, and -Z-(CH 2) n -SiR 1 a R 2 b X c wherein R 1 is a C1 to C20 hydrocarbon group wherein at least one hydrogen atom on carbon atoms at positions 1 to 3 is replaced with halogen, -OR 3, -NR 4 R 5, -N=R 6, -SR 7 (in which each of R 3, R 4, R 5, and R 7 is a hydrogen atom or a C1 to C20 substituted or unsubstituted hydrocarbon group, and R 6 is a divalent C1 to C20 substituted or unsubstituted hydrocarbon group), a C1 to C20 perfluoroalkyl group, or a cyano group; R 2, and X are defined as mentioned in formula; Z represents a linking group selected from -CO-O-, -O-CO-N(R 9)-, -N(R 9)-CO-O-, -N(R 9)-CO-N(R 9)-, -S-CO-NH-, -NH-CO-S-, and -S- wherein R 9 represents hydrogen or a C1 to C18 hydrocarbon group optionally substituted with halogen; n represents a number of 1 to 8; a is 0, 1, or 2, b is 0, 1, or 2, and c is 1, 2, or 3, provided that the condition: a+b+c = 3 is satisfied; and in the case that a plurality of R 1 s, R 2 s, or Xs exist, they may be the same as or different from each other. a polyether polymer containing a reactive silyl group represented by the following formula; and at least one of a polyether polymer containing a reactive silyl group represented by the following formula and a (meth)acrylic polymer containing a reactive silyl group represented by the following formula: -W-CH 2 -SiR 1 a R 2 b X c wherein R 1 is a methoxymethyl group; R 2 represents a C1 to C20 hydrocarbon group, a C6 to C20 aryl group, a C7 to C20 aralkyl group, or a triorganosiloxy group represented by R 0 3 SiO- wherein each of three R 0 s is a C1 to C20 hydrocarbon group and they may be the same as or different from each other; X represents a hydroxy or hydrolyzable group; W represents a linking group -O-R 8 - wherein R 8 represents a divalent C1 to C8 hydrocarbon group, a is 1 or 2, b is 0 or 1, and c is 1 or 2, provided that a+b+c = 3 is satisfied; and in the case that a plurality of R 1 s, R 2 s, or Xs exist, they may be the same as or different from each other, -V-SiR 2 d X 3-d wherein R 2 and X are defined as mentioned in formula; V represents a divalent C2 to C8 hydrocarbon group; d represents any of 0, 1, and 2; and in the case that a plurality of R 2 s or Xs exist, they may be the same as or different from each other, and -Z-(CH 2) n -SiR 1 a R 2 b X c wherein R 1 is a C1 to C20 hydrocarbon group wherein at least one hydrogen atom on carbon atoms at positions 1 to 3 is replaced with halogen, -OR 3, -NR 4 R 5, -N=R 6, -SR 7 (in which each of R 3, R 4, R 5, and R 7 is a hydrogen atom or a C1 to C20 substituted or unsubstituted hydrocarbon group, and R 6 is a divalent C1 to C20 substituted or unsubstituted hydrocarbon group), a C1 to C20 perfluoroalkyl group, or a cyano group; R 2, and X are defined as mentioned in formula; Z represents a linking group selected from -CO-O-, -O-CO-N(R 9)-, -N(R 9)-CO-O-, -N(R 9)-CO-N(R 9)-, -S-CO-NH-, -NH-CO-S-, and -S- wherein R 9 represents hydrogen or a C1 to C18 hydrocarbon group optionally substituted with halogen; n represents a number of 1 to 8; a is 0, 1, or 2, b is 0, 1, or 2, and c is 1, 2, or 3, provided that the condition: a+b+c = 3 is satisfied; and in the case that a plurality of R 1 s, R 2 s, or Xs exist, they may be the same as or different from each other.