α-Fe 2 O 3 fine particles have been prepared by a mechanochemical process and a solution process. α-Fe 2 O 3 nanoparticles with aggregates composed of the several tens nm primary particles were produced by the mechanochemical process. The nanoparticles were applied to the electrode as an active material for all-solid-state lithium batteries and the electrochemical properties of the cell were investigated. Typical charge–discharge curves, as seen in the liquid type cell using the α-Fe 2 O 3 nanoparticles as an electrode were observed in the all-solid-state cell. The first discharge capacity of the cell of about 780mAhg −1 was, however, smaller than the capacity of a cell using α-Fe 2 O 3 particles prepared by the solution process, which were monodispersed particles of 250nm without aggregates. In order to develop electrochemical performance of all-solid-state batteries, it is important to use the electrode particles without aggregation which lead to the formation of good solid–solid interface between active material and solid electrolyte particles.C