In the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) collaboration, the Trap group has been working on an efficient accumulation of antiprotons and production of ultra slow mono-energetic antiproton beam, which is realized by a combination of an RFQD (Radio Frequency Quadrupole Decelerator) and a large multi-ring trap (MRT) installed in a super-conducting solenoid. We have succeeded to accumulate several million antiprotons. A mono-energetic antiproton beam of 10 eV has been extracted and transported through a specially designed beam line, which has a high transport efficiency and at the same time enabling differential pumping of more than six orders of magnitude between the MRT and a collision chamber. This configuration was adopted to make atomic collision experiments like ionization and antiprotonic atom formation processes and also to study spectroscopic nature of various meta-stable antiprotonic atoms under single collision conditions, which has never been possible. A new scheme of efficient positron accumulation has been invented employing high-density electron plasma and an ion cloud, which fits quite well with the UHV requirements of antihydrogen synthesis as well as other applications. A so-called cusp trap configuration has been proposed as a new synthesizer of antihydrogen, where antiprotons and positrons can co-exist in the same place even at low temperature. Because of the inhomogeneous magnetic field distribution of the cusp trap, (1) a low energy component of the antihydrogen atom so formed can be trapped for a macroscopic time, and (2) a high energy component emerges as an intensity-enhanced and energy-filtered spin polarized antihydrogen beam, which is suitable for measurements of the hyperfine splitting of antihydrogen, and could provide the magnetic moment of antiproton with some ppm accuracy.