Provided are a coagulation treatment apparatus capable of removing fine objects of removal from a fluid containing the objects of removal, and a coagulation treatment method using the apparatus. A coagulation treatment apparatus for a fluid according to the present invention includes a production device for introducing ions of metal belonging to Group 8 of the periodic table into a fluid containing objects of removal and for producing a coagulated substance in which the objects of removal and the metal ions are bonded to each other. Moreover, a coagulation treatment apparatus of another embodiment includes: the production device for introducing ions of metal belonging to Group 8 of the periodic table into a fluid containing objects of removal and for producing a coagulated substance in which the objects of removal and the metal ions are bonded to each other; and the introduction device for coagulating the objects of removal by introducing the coagulated substance produced by the production device into the fluid.