Abstract: Chemical conversion treatment agents for surface treating a metal substrate and a method for surface treating a metal substrate using the same are described in this disclosure. The chemical conversion agent includes at least one metal element, a fluorine element, and a co-condensate of a first silane coupling agent (A) and a second silane coupling agent (B).

Abstract: A chemical conversion treatment agent for surface treatment of a metal substrate, comprising: at least one metal element selected from the group consisting of zirconium, titanium, and hafnium; fluorine element; and a co-condensate of a silane coupling agent (A) and a silane coupling agent (B), wherein the silane coupling agent (A) is a silane coupling agent having a tri- or di-alkoxysilane group and an amino group, and the silane coupling agent (B) is a silane coupling agent represented by the following general formula (1): [in the formula, R represents an alkylene groups having 1 to 5 carbon atoms or the like, Z represents a cyclohexyl group optionally having an epoxy group or the like, a, b, and c each represent an integer of 0 to 3, provided that a sum of a, b, and c is 3, and a sum of a and b is 2 to 3, and x represents an integer of 1 to 3].