Today, it is clearly known that the electronic devices generate electromagnetic radiations unintentionally, which may contain critical information called compromising emanations (CE). CE is also known as TEMPEST radiation, which is a code name firstly used by an U.S government program. Every developed country has a TEMPEST Test Laboratory (TTL) connected to their National Security Agency (NSA). The main objective of these laboratories is to investigate equipment, systems, and platforms processing cryptographic information in terms of CE. TEMPEST tests might take very long time depending on the item under test. In this paper, a complete Automatic TEMPEST Test and Analysis System (ATTAS) developed in TUBITAK, BILGEM TTL is introduced. The system has the following properties, which are automatic system calibration unit, automatic test matrix generator based on the SDIP-27/1 standard, implementation of tunable and nontunable tests, automatic CE investigations, rendering of the CE of video display units, playing of the CE of audio signals, measurement of detection system sensitivity, zoning of TEMPEST equipment based on SDIP-28 standard, and generation of graphical results.