The present study aims at investigating the development of porous structure during steam gasification of woody char and its effect on macroscopic reactivity. The experiments were conducted in a temperature range of 600–800 °C using biochar, derived from entrained flow gasification of biomass. The results show that the gasification temperature has minor effect on porous structure development. The total surface area of char as well as the specific total pore volume increase significantly until a certain conversion at all temperatures.