To injection-mold a circular cylinder body of a semi-solid metal, in which fine primary crystals suitable for a semi-solid molding are dispersed, by automatically and smoothly containing the body in an injection sleeve with a horizontal shaft centre.

A whole open part 8b, the both ends of which are approximately vertically opened, is arranged at an intermediate position of the injection sleeve 8. Above the whole open part 8b, a container 20 of the circular cylinder body Mb of the semi-solid metal with a rotating means is arranged to incline to the shaft centre of the sleeve 8 and to freely rotatingly fix the both ends of the container 20 to a rotation axis 22a pivoted with a bearing 24, to be a tilting position at the top position and to be formed by a cylinder body introduceable with the cylinder body Mb. At the lowest position, the shaft centre of the container 20 becomes the horizontal state to coincide with the shaft centre of the sleeve 8 to be the consolidated cylindrical state by coinciding with the both shaft centres of the sleeve 8 and the container 20. During rotating of the container 20 from the time of receiving the body Mb at an inclining movement at the top position to the horizontal state, a bottom guide plate 30 sliding on the side face of the plunger tip 8a is arranged to fix to the sleeve 8.