This study was analyzed using fNIRS to find out which brain regions were activated in elementary school students (1st-2nd) to solve spatial tasks. Spatial ability was based on mental rotation, spatial visualization, and spatial orientation, and the research results were as follows. First, in mental rotation, spatial visualization, and spatial orientation, the DLPFC was activated significantly higher, and the VLPFC was activated significantly lower. Second, OFC appeared only for spatial orienting, with significantly lower activation in both brain regions. Third, boys had significantly higher activation of many channels in the DLPFC and VLPFC, while girls had significantly lower activation of only one channel of the VLPFC. And in terms of brain activity differences between genders, boys showed higher activation in the DLPFC, FPPFC, and VLPFC than girls. The use of various brain regions in boys suggests the possibility of using more diverse strategies and seeking alternatives when solving new types of spatial tasks that are difficult or unfamiliar.