A connecting device for inspection includes a probe head configured to hold electric contacts and optical contacts such that tip ends of the respective contacts are exposed on a lower surface of the probe head, and a transformer including connecting wires arranged therein and optical wires penetrating therethrough. The respective proximal ends of the electric contacts and the optical contacts are exposed on an upper surface of the probe head, and tip ends on one side of the connecting wires electrically connected to the proximal ends of the electric contacts and connecting ends of the optical wires optically connected to the proximal ends of the optical contacts are arranged in a lower surface of the transformer. A positional relationship between the tip end of the respective electric contacts and the tip end of the respective optical contacts on the lower surface of the probe head corresponds to a positional relationship between an electrical signal terminal and an optical signal terminal of a semiconductor device.