A chemical solution distributing apparatus which is installed in a water tank in water closets or the like and distributes chemical solutions periodically in the water tank including a bottomed tubular apparatus main body which has an opening at its lower end; a chemical retaining section which is present inside this apparatus main body and mounts/retains chemicals; and a drawn-water passage section which is installed outside the apparatus main body and in which one end thereof is connected to the inside of the apparatus main body via the opening while the other end thereof is positioned higher than the lower end of the apparatus main body; wherein the chemical retaining section has holes in order to mix chemicals with the water inside the apparatus main body or inside the water tank; and wherein a check valve to allow release of air inside the apparatus main body to the outside is also formed.