The present invention relates to a composting apparatus using solid-phase anaerobic fermentation, wherein the composting apparatus comprises a solid-phase anaerobic fermentation unit (1), a pre-treatment unit (3), and a post-treatment unit (4). As for the solid-phase anaerobic fermentation unit (1), a low-molecular weight compound of organic waste, which is pre-treated under oxygen-free conditions obtained by overlapping an opened upper portion of an anaerobic fermentation bath (11) buried underground with a double cover (13), is subjected to methane fermentation while being stirred by a stirring unit (2), thereby making compost, and the biogas generated at the time of the methane fermentation is collected through a collection unit (14) installed in the ceiling. The pre-treatment unit (3) is connected to the anaerobic fermentation bath (11) underground. As for the pre-treatment unit (3), a first fermentation bath (31) receives the organic waste therein, and allows the organic waste to stay for about several hours to several days, thereby converting the organic waste into a low-molecular compound through hydrolysis and acid fermentation, and a substitution bath (32) receives the low-molecular weight compound together with the biogas therein to convert an aerobic state into an anaerobic state through a substitution reaction, and supplies the anaerobic state of low-molecular weight compound to the solid-phase anaerobic fermentation unit (1). As for the post-treatment unit (4), a post-aging bath (41) connected to the anaerobic fermentation bath (11) underground receives some of fermented compost, and ages or carries out the received fermented compost.본 발명은 고상 혐기발효 퇴비화 장치에 관한 것으로, 이를 위해 지하에 매설되는 혐기발효조(11)의 개방된 상부에 덮개(13)를 2중 중첩시켜 산소가 없는 조건 하에서 전처리된 저분자 화합물형태의 유기성폐기물을 교반수단(2)에 의해 교반하면서 메탄발효시켜 퇴비화하고, 메탄발효시 발생되는 바이오가스는 천정 더그매공간에 설치된 포집부(14)를 통해 포집하는 고상 혐기발효부(1)；와, 지하에서 혐기발효조(11)와 연설되고, 1차 발효조(31)의 내부로 유기성폐기물을 공급받아 수시간 내지 수일 정도 체류시켜 가수분해와 산발효에 의해 저분자 화합물형태로 변환하고, 저분자 화합물을 치환
