To form perforation in a hinge part as a single line and carry out punching in such a state that both ends of the perforation line continues smoothly to a punching contour line curve of a container body and a lid part.

A method of producing a plastic packaging container comprising a container body provided with a body concave part, a lid part provided with a lid concave part corresponding to the container body and a hinge part and provided with a single perforation line extending in the lengthwise direction in the hinge part, with both ends of the perforation line continuing smoothly in a flabellate form to a punching contour line curve of the container body and the lid part, comprises a first step of forming an arrangement of the body concave part and the lid concave part in a plastic sheet, a second step of forming a separation perforation line between the body concave part and the lid concave part and a third step of punching along a closed contour line surrounding the arrangement of the body concave part and the lid concave part.