The present invention provides a precursor ceramic composition containing at least one of Ca and PO4, having a higher solubility in H2O than octacalcium phosphate, and having a volume of more than 2.0 mm3. The precursor ceramic composition is immersed in a solution containing a composition that is not included in the precursor ceramic composition among the compositions of PO4 and H2O, and the precursor ceramic composition is reacted, so that at least a part of the precursor ceramic composition is converted to calcium octaphosphate. The present invention provides a method for producing a molded article containing octacalcium phosphate having a volume of 2.0 mm3 or more, which is characterized by being converted to [Selection] Fig. 3-2本発明は、Ｃａ及びＰＯ４の少なくとも１つを組成に含み、Ｈ２Ｏへの溶解度が第八リン酸カルシウムより高く、体積が２．０ｍｍ３超の前駆体セラミックス組成物を、第八リン酸カルシウムの組成であるＣａ、ＰＯ４、Ｈ２Ｏの組成のうち前記前駆体セラミックス組成物に含まれない組成を含む溶液に浸漬し、前記前駆体セラミックス組成物を反応させて、前記前駆体セラミックス組成物の少なくとも一部を第八リン酸カルシウムへ変換することを特徴とする、体積が２．０ｍｍ３以上の第八リン酸カルシウムを含む成形体の製造方法等を提供する。【選択図】図３－２
