It is an object of the present invention to provide a solar boiler system that can suppress the installation cost for a solar heat collector and significantly improve gross thermal efficiency while minimizing a rise in air temperature resulting from the collected solar heat. The solar boiler system of the present invention includes a boiler 10 for burning fossil fuel; a primary air system for pneumatically transporting pulverized fossil fuel to a burner attached to the boiler 10; a secondary air system for supplying preheated air for combustion to the boiler 10; and a secondary air superheater 7 provided at the secondary air system, the secondary air superheater 7 further superheating the preheated air for combustion with solar thermal energy.
