To provide an organic matter reforming apparatus effectively reforming hardly decomposable organic material, and turning into compost material quickly and high efficiently composted.

Treating objects charged into a casing 11 from a charge port 12 are sent to a discharge port with a pair of double shaft driven first screw bodies 21, compacted being prevented from the reverse flow by a pair of second screw bodies 22, and led between the outer peripheral faces of a pair of drums 23 and inner faces 16 of second inner walls to be pressure-crushed. When leading the treating object from a crushing chamber housing the drums 23 to an end face camber, the crushing pressure is abruptly released to expand and soften the treating object to separate fiber bundles. The expanded and softened treating object is cut with a rotary blade and discharged. Even if the treating object is a wooden material, firm structure formed by cellulose, hemicellulose and lignin can be effectively decomposed, therefore, the compost material efficiently composted in a shorter time than in the past can be obtained.