An object of the present invention is to provide a trophic factor releasing agent and an inflammatory disease treating agent in which an amount of trophic factors released from cells in a cell transplantation treatment or the like is increased. According to the present invention, there is provided a trophic factor releasing agent including a cell structure that includes biocompatible polymer blocks and cells and in which a plurality of the biocompatible polymer blocks are disposed in gaps between a plurality of the cells, in which a size of one of the biocompatible polymer blocks is 20 μm to 200 μm, and trophic factors are released from the cells.