This manual provides comprehensive operating and maintenance instructions for Hitachi Hydraulic Excavator models Zaxis 450-3, 450LC-3, 470H-3, 470LCH-3, 500LC-3, and 520LCH-3. These excavators are engineered for demanding construction and earthmoving tasks, offering robust performance and reliability. With a focus on operational efficiency and user safety, the Zaxis series is designed to meet the rigorous requirements of professional work sites, ensuring productivity and durability. The purpose of this manual is to serve as an essential resource for owners, operators, and service technicians. It covers critical aspects including detailed safety guidelines, component identification, operating procedures for various work modes, assembly and disassembly instructions, and a thorough maintenance schedule with step-by-step procedures for lubrication, fluid changes, filter replacements, and system checks. Additionally, the manual includes troubleshooting guidance, detailed technical specifications, and information on optional attachments, enabling effective upkeep and repair to maintain the excavators' optimal performance and longevity.