The book "Ultra-Low Voltage Nano-Scale Memories" offers a comprehensive analysis of the latest developments in nanometric and sub-1-V memory LSI, which play a crucial role in energy-efficient systems. It systematically addresses the emerging challenges at the device, circuit, and system levels, particularly concerning the reliable high-speed operation of memory modules and the associated logic circuits. The authors thoroughly explain the effectiveness of solutions at the device and circuit levels by clarifying the noise components in an array and highlighting the essential differences in the ultra-low voltage operation of DRAMs and SRAMs. Additionally, various types of on-chip voltage converters are discussed, which are necessary to address issues related to internal power supply. This authoritative work is aimed at engineers, researchers, and students interested in ultra-low voltage nano-scaled memory LSIs.