This study quantifies the factors contributing to foreign direct investment (FDI) using data from a questionnaire-based survey of Japanese manufacturing firms with overseas operations.　The results of our analysis echoed that of previous research, demonstrating that in addition to company size, the effects of R&D and marketing capabilities on FDI were statistically significant.　Notably, R&D capability exerted a stronger effect than marketing capability, which led us to conclude that technical knowledge is an important firm-specific advantage among firms embarking on FDI.