To provide a rupturing device of a beautifully crackable connecting rod, and a manufacturing method of the ruptured connecting rod.

This rupturing device of the connecting rod has first and second support members 31 and 32 movably arranged in the mutually separating direction on a pallet base 30 for placing the connecting rod, and supporting a large end part and a rod part of the connecting rod, a half-split-shaped mandrel 40 suspended by these support members, and composed of two mandrel half parts 41 and 42 having respective outer peripheral surfaces respectively abutting on and fitting to an opening part inner surface of the large end part, a wedge 25 uniformly separating and expanding the respective mandrel half parts, and an actuator 21 applying a load to the wedge. A universal joint 70 is interposed between the wedge and the actuator, and driving force is transmitted to the wedge from the actuator via the universal joint.