To recycle a soil manufacturing apparatus for efficiently converting paper chips formed by finely cutting paper or wood into soil.

A fermentation tank 1 is composed of a paper chip feeder 2 and a fermentation tank body 10. The chip feeder 2 has a supply port 3 of the paper chips, a supply port 4 of humus soil and a spiral sending device 5. The fermentation tank body 10 has a spiral feeding device 11 transferring the paper chips and humus soil mold, heaters 14, sprinklers 15, openable/closable ceiling parts 16 and sucking/ discharging fans 17. A control device is provided for controlling heating amount by the heater 14, spraying amount by sprinklers 15, supply amount of humus soil, transferring speed of the spiral feeding device 11, and opening degree of the ceiling parts 16 to prescribed amounts according to the charged volume of paper chips, when signals are inputted showing charged volume of the paper chips to the fermentation tank 1, to quickly convert the paper chips into the soil in the fermentation tank body 10.