To provide a method for producing a solid fuel in which the content of chlorine can be significantly reduced than before.

There is provided an improvement in a method for producing a solid fuel including supplying a powdered waste which is dried, ground, and sorted through a waste collection pit 2, a primary crushing and sorting means 17, a drying oven 8, and a secondary crushing and sorting means 18, successively, to a forming machine 12, in which the powdered waste is compressed to produce a solid fuel having a specified shape. The improved method includes recovering waste by separate recovery of combustible waste and plastic waste and appropriately applying the following three means to reduce the chlorine content of the solid fuel to 0.3 mass% or less: means 1: previously reducing polyvinyl chloride from the plastic waste separately recovered from the city; means 2: separately heat-treating off-line the waste water accumulated in a waste water pit attached to the waste collection pit; and means 3: mixing a biomass fuel with the waste.