To provide an apparatus enabling a large quantity of fish bodies to be treated at low cost at a small-space treatment site.

This fish body treatment apparatus comprises the following components: a guide hopper 30 openable left and right, having on the lower part a pair of inclined guide plates 35 always urged toward the center and making even the posture of fish bodies 20 to-be-charged and allowing them fall down via an outlet 32 on the lower part, a cutting means 40 constructed by spacedly placing left and right a pair of circular saw teeth 43 disposed right under the outlet 32 and about the outlet 32 as the center through making their orientation even longitudinally and with a part thereof superposed on each other, a rotatingly driving means 50 for respectively rotating the pair of circular saw teeth 43 in such a direction as to enfold fish bodies 20 inward so as to be cut by the pair of saw teeth 43, and a separating member 60 for separating inner bone parts 21 and left and right flesh parts 22 respectively cut by the cutting means 40 and for dropping them.