This paper, using Japanese firm-level data, presents findings about innovative activities in the service sector and the role of patents and trade secrets on innovation. According to the analysis, first, service firms have fewer product innovations than do manufacturing firms, but the productivity of innovative service firms is very high. Second, service firms have a low propensity for holding patents, but their holding of trade secrets is comparable to that of the manufacturing firms. Third, patents and trade secrets have positive relationships with product innovations, and the effects are quantitatively similar in magnitude in both the manufacturing and the service sectors. On the other hand, a positive relationship between trade secrets and process innovations is found only in the manufacturing sector. These results suggest a pivotal role of the law protecting trade secrets on innovation and productivity growth in the service sector.