Provided is a semiconductor test apparatus that tests a device under test, comprising a test unit that tests a device under test; and a serial transmitting section that transmits transmission data back and forth between the test unit and a control section controlling the test unit. The serial transmitting section includes a data sending section that sends a plurality of pieces of the transmission data in a predetermined order; a resending control section that resends the transmission data; and an expected acknowledgement ID storage section that stores an expected acknowledgement ID indicating identification data that is expected to be attached to an acknowledgement signal received on a transmission side. The resending control section judges whether resending is necessary based on (i) whether resend count information indicates that a piece of transmission data is resent data and (ii) the expected acknowledgment ID in the expected acknowledgement ID storage section.