One of the biggest challenges faced in building the capacity of armed forces to operate in cyberspace is to attract, improve and retain expert staff. Cyberspace is, after all, the only operational domain that has been entirely created by people, so people have to be able to use it and also to constantly create it anew. According to the estimates cited e.g. by ENISA in 2019, there was a shortage of over 4 million cybersecurity specialists on a global scale, and approx. 65% of organisations declared staff shortages in the area of tasks related to cybersecurity. A real race for specialists in this domain is observed among both international corporations and domestic companies from plenty of industries, critical infrastructure operators and, finally, intelligence services. In this inter-sectoral, global competition, the public sector (which includes the military) is often in a difficult situation because of the limited possibilities of using financial incentives. Considering the needs and constraints, a resources-building strategy should be adopted that uses all the advantages found within the range of influence of the military sector. The article discusses them using various approaches, based on actions successfully implemented by the Polish Ministry of National Defence under the programme of capacity building in the armed forces to operate in cyberspace. The first aspect the image, motivation and challenges. Service in the cyber armed forces component provides the opportunity to reach areas unattainable anywhere else, including constant interaction with a well-prepared and highly motivated enemy. The second point for consideration is education and continuous improvement. The possibilities to recruit experts who already have a good position in the commercial market are limited. Therefore, development of the military education system is the best way to ensure a steady inflow of staff. In Poland, it was decided both to use military academies for this purpose and a real educational ecosystem is being created and constantly developed, also including a military IT secondary school and a dedicated non-commissioned officer school. Civilian secondary schools run (in co-operation with the Ministry of National Defence, MON) profiled vocational training classes, students of civilian universities undergo military training in cybersecurity, and the performance improvement will be managed by the Expert Cybersecurity Training Centre. The third aspect is the Territorial Defence Force, which gives the opportunity in the Cyberspace Operations Team to combine military service and to continue previous professional work on an extremely competitive market.