Provided are (1) a hydrophilic treatment coating composition containing a compound that contains a radical reactive functional group and a sulfonic acid alkali metal salt group, a radical polymerization initiator, and a polar compatibilizer, (2) a hydrophilic treatment coating composition containing a silane coupling agent that contains a radical reactive functional group, a compound that contains a radical reactive functional group and a sulfonic acid alkali metal salt group, a radical polymerization initiator, and a polar compatibilizer, (3) a hydrophilic treatment coating composition containing a compound that contains a functional group that reacts with a reactive functional group of a silane coupling agent in a surface layer, and a sulfonic acid (alkali metal salt) group, and a polar compatibilizer, and (4) a hydrophilic treatment coating composition containing a silane coupling agent that contains a reactive functional group, a compound that contains a functional group that reacts with the reactive functional group and a sulfonic acid (alkali metal salt) group, and a polar compatibilizer.