Water/oil-repellent coating composition

A water/oil-repellent coating composition comprising an organosilicon compound (A), a metal compound (B), and a solvent (C),

• wherein at least one first hydrocarbon chain-containing group and at least one hydrolyzable group are bonded to a silicon atom in the organosilicon compound (A),
• wherein at least one hydrolyzable group is bonded to a metal atom in the metal compound (B),
• wherein a second hydrocarbon chain-containing group having a length shorter than the length of the first hydrocarbon chain-containing group may be bonded to the metal atom in the metal compound (B),
• wherein the first hydrocarbon chain-containing group is a hydrocarbon group,
• wherein the hydrocarbon group has a carbon number of not less than 7 and not more than 17,
• wherein a molar ratio of the metal compound (B) to the organosilicon compound (A) as metal compound (B)/organosilicon compound (A) is not less than 18 and not more than 48, and
• wherein the solvent (C) is methanol, ethanol, propanol, or butanol.