Abstract: A plug-opening device for a sealed type container, an opening of which is sealed with a sealing plug having a plug-opening tab, comprising a gripping mechanism for gripping the tab of the sealed container at a plug-opening position; and a plug-opening mechanism for moving the gripping mechanism passing through a position above the sealed container obliquely and upwardly on the side opposite to the position for the tab. The plug can be detached automatically from the opening reliably.

Abstract: A plug-opening device which includes a rod capable of moving forwards or backwards, and a plug-opening member having elastic leaf springs, for urging against a circumferential side of a plug of a specimen container, attached to the rod in the longitudinal direction. The plug-opening member preferably includes a plurality of leaf springs in a stack formation, wherein an end portion of a higher leaf spring relative to another end portion of a lower leaf spring, adjacent to the higher leaf spring, extends further away from the end portion of the rod. More preferably, the plurality of leaf springs are attached with a gap being formed between upper and lower leaf springs. The plug-opening device can reliably, effectively, and smoothly open a plug of a specimen container with one stroke of the cylinder rod.