The ICT sector is one of the most important industries in the world, thanks to the high added value of its production. The competitive advantage of such a sector depends (among other things) on the ability to acquire knowledge from various available resources. ICT firms need to be able to adapt and react flexibly due to the high dynamics of development in the field of information and communication technologies. These firms are trying to use different knowledge resources, engaging in knowledge cooperative networks in a globalized innovation environment. Determinants of this environment are also largely influencing their production function. Due to the importance of the field and the level of public funding, it is necessary to study the impact of different innovation sources on the ability of ICT firms to produce innovations. Our study is a macroeconomic study of the ICT sector in the EU using data from Eurostat (Community Innovation Survey). With three own regression models, we demonstrate that firms in the ICT sector often use resources from the group of cooperating companies, acquire the existing know-how, licenses and patents on the market, and pay great attention to their own employees as a source of potential knowledge. Results of the research so far confirm the negative impact of public organizations on innovation (or R&D) performance of the ICT firms. In the context of public funding of support for R&D activities in the ICT industry, it is possible to talk about significant allocation inefficiencies or possibly too long-term investments with uncertain results.