Disclosed is a test device for testing a high-frequency and high-speed semiconductor. The test device includes a probe supporting block formed with a tube accommodating portion along a test direction; a conductive shield tube accommodated in the tube accommodating portion; and a probe accommodated and supported in the shield tube without contact, the tube accommodating portion including a conductive contact portion for transmitting a ground signal to the shield tube. When a high-frequency and high-speed semiconductor or the like subject is tested, the test device easily and inexpensively prevents crosstalk between the adjacent signal probes and improves impedance characteristic.