This carrier system carries at least one type of sensitizing dye described in (A) below and at least one type of sensitizing dye described in (B) below: (A) a sensitizing dye having a π-conjugated group and at least one anchor group, wherein the π-conjugated group and every one of the anchor group(s) are connected by a spacer having at least one alkylene and having an atomicity of 5 to 20; and (B) a sensitizing dye having a π-conjugated group and at least one anchor group, wherein the π-conjugated group and at least one anchor group are connected by a direct bond or by a spacer having at least one alkylene and having an atomicity of 1 to 4. In (A) and (B), the spacer is composed of carbon atoms, or carbon atoms and oxygen atom(s) etc., under predetermined conditions (see Description), and may have a branched chain or a ring structure.