Born in Zagreb, Čermak became a small businessman in the 1980s. In the 1990s, he entered the oil business.
Between 1990 and 1991, Čermak held the position of Vice President of the Executive Board of the Croatian Democratic Union (HDZ) and also served as an advisor to the President of the Republic of Croatia, Franjo Tuđman. In 1991, he was appointed the Assistant Minister of Defence in the Croatian Government, a position he held until 1993. While in this position and thereafter, he held the rank of Colonel General.
He was succeeded in this position by his former chauffeur, Vladimir Zagorec.