A fluid handling apparatus 10 has a plurality of fluid handling subassemblies 16, each of which is mounted in a corresponding one of mounting recessed portions 14 of a plate body 12. Each of the fluid handling subassemblies 16 includes: an injecting section 26 for injecting a fluid; a fluidized section 28 for receiving the fluid from the injecting section 26 to allow the fluid to continuously flow downwards; a fluid housing chamber 30 for receiving the fluid from the fluidized section 28; a wall portion 20 formed so as to extend in substantially vertical directions between the fluid housing chamber 30 and the fluidized section 28; an opening 20a for allowing the fluid in the fluidized section 28 to enter the fluid housing chamber 30; and a surface-area increasing means (22, 32, 34) for increasing the area of a contact surface with the fluid in the fluidized section 28.