A test socket unit for electrically connecting a test object and a test circuit device. The test socket unit includes: a plurality of support locking pins configured to be stationarily installed on the surface of the test substrate; a socket main body configured to support a plurality of probes for signal transmission; a floating plate configured to include a pin guide hole in which the support locking pin is inserted; an elastic member configured to be interposed in between the socket main body and the floating plate; and at least one locking member configured to include a locking portion engaged with the locking engaging portion and prevented from separating upward by the locking stopper.