Lithium solid electrolytes promise the potential to replace organic liquid electrolytes and thereby improve safety of the next-generation batteries. Among the electrolytes proposed, the sulphide system is a candidate for practical batteries because of their high ionic conductivity; the Li10GeP2S12 (LGPS) phase exhibits high ionic conductivity of over 10-2 S cm-1 at room temperature and is promising for applications requiring batteries with high powers and energy densities. The present study focuses on several topics of the all solid-state system using the inorganic electrolytes. (i) Material varieties of the LGPS system may provide suitable combinations of the electrodes and the electrolyte. To improve the materials variety, the substitution systems with the LGPS type structure were examined, and their phase diagram, structure and ionic conduction were studied. (ii) The combination with high-voltage electrode or high-capacity electrode may provide high capacity systems. The all solid-state batteries using various electrode materials were examined. (iii) The reaction at the electrolyte/electrode interface is the important issue to improve the stability and rate capabilities. High resistance at the interface of the solid-state system might prevent their usage for high current battery systems. Reactions at the interface were also examined. Based on these experimental results, the battery characteristics of the all solid-state system using LGPS electrolytes will be discussed.