The invention provides a method capable of manufacturing a micropump check valve, inexpensively and without much trouble or time, which does not cause disadvantages even if a material that dissolves an adhesive is contained in the fluid, and which allows bonding with high accuracy. After a valve forming member and a valve receiving member are bonded, a valve receptor is projected towards a valve part and pretension is applied. Thus, the valve forming member and the valve receiving member can be satisfactorily bonded through a solid phase diffusion bonding method and the like using a relatively inexpensive material, such as stainless steel, without using an adhesive, and the pretension is not reduced when in the annealing state.