A blister packing machine includes: a conveyor that conveys a belt-like container film having a pocket portion forming area and an expected mounting part; a preheating device that preheats the container film conveyed by the conveyor; a pocket portion forming device that forms a pocket portion in the container film softened by the preheating device; and a tension applier that applies a tension along a width direction of the container film to at least the pocket portion forming area. The pocket portion forming device forms the pocket portion while the tension applier applies the tension to the container film, the container film has an edge area between an edge in the width direction and the expected mounting part, and the tension applier includes a projection that applies the tension to the container film by pressing the edge area to form a protruding portion in the container film.