A protective frame structure includes: a lower frame; an intermediate frame that is interlinked with the lower frame and is situated above the lower frame; and an upper frame that is interlinked with the intermediate frame and is situated abobe the intermediate frame, wherein a mounting space in which a battery module is configured to be mounted is formed between the lower frame and the intermediate frame, an upper space is formed between the intermediate frame and the upper frame, and the intermediate frame is deformed upward when an external load has been applied to the protective frame structure.