To prevent a thin-walled part from sticking out of a container after an axis part is removed in an injector applied to human body that is provided with the container body and the axis part with a knob part connected with the container body through the thin-walled part.

A thin-walled part 6 constitutes a bottom wall of a concave part 9 formed on an outside surface of a container body 2. A forming mold of a container 1 is provided with a cavity mold 11 that defines an outside shape of the container body and a slide mold 13 that defines the external shape of the axis part and the internal shape of the concave part. The slide mold 13 is composed of several split molds 13a and 13b divided to diameter direction of the axis part. Each split mold 13a and 13b is constituted to make it possible to slide to the outside of the diameter direction in accordance with axial separation against the cavity mold 11.