A 1 K bit associative memory LSI has been fabricated using E/D nMOS micro fabrication technology. This LSI has been designed to carry out all the functions necessary to realize a high performance data search system. A retrieval function for processing searched out data is implemented on the chip, so as to realize a self-operative, large-capacity associative memory. By means of this function, searched out data can be retrieved every two cycles in the basic system, and every four cycles in a lengthy data search system constructing of using plural chips of this LSIs. Furthermore, a search function for similar data is implemented so as to allow use of the associative memory over a wide range of applications. The measured minimum cycle time, and power dissipation of the associative memory are 100 ns, and 1.2 W, respectively.