In this study, we determine whether coniferous plantations in the cool temperate zone of northeast Japan, with few natural evergreen forests, can serve as a habitat for Japanese squirrels. We also examine whether Japanese squirrel habitat use in cedar plantations varies based on forest structure. Our results showed that the relative frequency of squirrel occurrence, determined by camera traps and the number of feeding signs, was significantly higher at cedar forest survey sites than other forest types. The best generalised linear model for frequency of occurrence included the number of standing trees, canopy openness and understory visibility, while the best model for the number of feeding signs included total basal area, canopy openness and the number of walnut trees. The results suggest that cedar plantations within the study area serve partially as a habitat for squirrels, replacing natural evergreen trees. Furthermore, squirrel habitat use differed between cedar plantations based on forest structure, confirming the importance of a diverse forest structure for squirrels. Therefore, when considering the conservation and management of small arboreal mammals that use such plantations, they must include diverse structures to facilitate their use as a habitat.