To resolve the problem that when compost and stockbreeding animal excreta are conventionally treated to obtain fertilizer or fuel, smell of the compost and the excreta cannot be removed even by drying and exerts adverse influence on living environment of residents living in the vicinity.

After a deodorant solution is poured into the compost and the excreta or the like of the stockbreeding animal, the compost and the excreta are agitated together with the deodorant solution and then the agitated liquid is subjected to solid-liquid separation to separate solid content from liquid. The solid content is blended with wood pieces and wood chips and obtained mixture is pulverized and dried. Thereby the mixture can be preserved in a smell-free state and further no malodor is produced when burned.