The Active Segmented Mirror is a key subsystem of the Active Phasing Experiment. The size of the ASM is 154 mm in diameter. It will be used to test new types of phasing sensors recently developed within the ELT design study supported by the European Union. To our knowledge it is the first time that such miniature active optics composed of hexagonal segments having 3 degrees of freedom with a resolution of the order of a few nanometers and a range of several micrometers is manufactured. The ASM is composed of 61 hexagonal segments called "modules". Each module is assembled, glued and integrated from standard (piezo-actuators) and custom-made (mirrors, mechanics) parts procured from industries. The ASM has been designed and integrated at the European Southern Observatory. Specifications, designs, assembly tools, hand work skills, electronics, software, control algorithms and test procedures are the field of competences required to obtain in the end a "plug and play" product. The concept of the ASM is tested and validated by a prototype version composed of 7 modules equivalent of the central area of the ASM itself. The design, integration and results of the ASM tests are presented.