The internal airflow characteristics in a cross-ventilation model were investigated using split-film probes capable of measuring directional velocity components. The penetrating flow entered the inlet at steep declining angles due to the front eddy and flowed downwards to the floor. The internal turbulence spectrum of the main stream penetrating the inlet remained the same as that of the oncoming flow, but the spectra of other components were produced by the internal turbulence, whose eddy size was determined explicitly by the size of the model. The flow exiting from the outlet moved upwards due to the outside re-circulating eddy. The ventilation flow rates increased in the range of 40°⩽θ⩽60° for the incidence angle of the oncoming flow because the dynamic pressure at the inlet increased due to the change of the separated flow patterns around the model. The discharge coefficient for the inlet remained almost constant over a wide range of wind directions for the aspect ratio equivalent to 1:2.