This paper examines various channels and issues for foreign firms to invest in inter-Korean economic cooperation with the assumption that inter-Korean economic cooperation can be resumed after sanctions against North Korea have been lifted, and the same treatment is applied to foreign firms. Foreign firms’ investment in inter-Korean economic cooperation will provide a new opportunity for foreign firms to earn stable profits, while also playing a role in further solidifying the establishment of peace on the Korean Peninsula. Now, inter-Korean relations have fallen into difficulties due to sanctions against North Korea and the coronavirus pandemic, making it difficult to resume inter-Korean economic cooperation or to expect foreign firms to invest in inter-Korean economic cooperation. However, if inter-Korean economic cooperation is resumed, foreign firms’ investment in inter-Korean economic cooperation will be prioritized.