Integrated high-speed probe system

An integrated high-speed probe system is provided. The integrated high-speed probe system includes a circuit substrate for transmitting low-frequency testing signals from a tester through a first probe of the probe assembly to a DUT, and a high-speed substrate for transmitting high-frequency testing signals from the tester to the DUT. The high-speed substrate extends from the upper surface of the circuit substrate in the testing area to the lower surface of the circuit substrate in the probe area for being adjacent to the probe assembly and electrically connecting the second probe. In this way, the tester can transmit testing signals of different frequencies through the integrated high-speed probe system.