Aspects of development of experimental techniques at Geodynamics Research Center (GRC), Ehime University, using Kawai-type multianvil apparatus (KMA) for various studies in deep Earth mineralogy, have been reviewed in conjunction with the author’s scientific achievements in this field. Precise measurements of some physical properties of minerals at the pressure and temperature conditions corresponding to certain depths of the lower mantle are now possible, by combinations of synchrotron radiation, advanced anvil materials, new cell designs, and ultrasonic and other techniques using KMA. KMA has also been used to synthesize ultrahard nano-polycrystalline diamond (NPD) by direct conversion from graphite. NPD has potential as new hard material for generation of higher pressures, and challenges in producing large (∼1 cm) NPD and its application to various apparatus have just started at GRC and other related laboratories.