This research aims to build a practical mobile robotic system to be used in actual humanitarian demining tasks. The basic system consists of a manipulator mounted on top of a mobile platform. For the purpose of building a practical and versatile mobile platform, the authors have already developed a 4-wheel autonomous buggy system called "Gryphon", as discussed in previous works. This paper addresses the development of an energy-efficient weight-compensated manipulator, which is composed of a 5-node parallel linkage. The manipulator was especially designed for antipersonnel mine detection and removal tasks. The weight-compensation concept and the principle of operation are discussed in detail, and the validity and usefulness of the manipulator, as well as of the whole robotic system, are demonstrated by real experiments.