To provide the method for connecting two constitutional elements with each other and assemblies inexpensibly with ease without being accompanied by inconveniences experienced in the past.

A diaphragm 14 is disposed to a post which is integrally formed with a valve base 11 so as to be erected, cutting is then performed, the almost simultaneous, deformation of the post for mounting the diaphragm to a specified position thereby allows the valve diaphragm 14 to be connected with the valve base 11, cutting and deformation as mentioned above allows the post to be cut in at two places in the longer direction, a center portion 21 and two outer side portions, 22 and 23 capable of being radiused, are formed, and they are bent outward in such a way as to be parted from the center portion.