The invention provides an aramid thin sheet material comprising two components of aramid staple fibers and fibrillated aramid, or said two components and aramid fibrid, in particular, characterized by satisfying both of the following expressions (1) and (2):
[internal resistance] (μm)≦250 (μm) expression (1)
[Oken-type gas permeability] (sec/100 cm3)≧0.5 (sec/100 cm3) expression (2)
wherein the [internal resistance] is a resistance value calculated by the following expression (3):