Provided is a solid chemical agent housing body obtained by filling the inside of a storage container with a water-soluble solid chemical agent, wherein the storage container has: a housing space capable of housing a plurality of water-soluble solid chemical agents； an inflow port through which to-be-treated water is introduced into the housing space； and an outflow port through which the to-be-treated water is discharged from the housing space, wherein a portion or all the water-soluble solid chemical agents are layered in the vertical direction with water-soluble films being interposed therebetween such that at least a portion of said water-soluble films is situated above the inflow port and the outflow port.一種固體藥劑收容體，其於收納容器的內部填充有水溶性固體藥劑，且所述固體藥劑收容體中，該收納容器具有可收容多種水溶性固體藥劑的收容空間、使被處理水流入該收容空間的流入口及使被處理水自該收容空間流出的流出口，於該收容空間中，將水溶性固體藥劑的一部分或全部介隔水溶性膜而在垂直方向上積層，並將該水溶性膜的至少一部分配置於較該流入口及該流出口更靠上方處。
