PROBLEM TO BE SOLVED: To stably produce solid fuel having steady quality and a large calorific value.SOLUTION: A production system of solid fuel comprises: a biaxial crusher 11 for crushing paper and lumber selected from wastes into a predetermined size; a drier 15 for drying the paper and lumber; a first metering feeder 40 capable of supplying a predetermined amount of the crushed and dried paper and lumber; a uniaxial crusher 31 for crushing synthetic resin selected from the wastes into a predetermined size; a second metering feeder 42 capable of supplying a predetermined amount of crushed combustibles; a controller 95 for controlling so that the paper and lumber discharged from the first metering feeder 40 and the synthetic resin discharged from the second metering feeder 42 may be discharged at a predetermined weight ratio; and a solid fuel compression molding machine for mixing, heating, melting and pressing the paper and lumber supplied from the first metering feeder 40 and the synthetic resin supplied
