President Ivan Gasparovic and major Slovak NHL stars -- including Zdeno Chara, Marian Hossa and Marian Gaborik -- attended.
The service was held Thursday in Trencin's arena in western Slovakia, where Demitra began his career in the top Slovak league in 1992.
Demitra was among 37 players, coaches and staff of Russia's Lokomotiv Yaroslavl hockey club who died last week when their Yak-42 jet crashed outside Yaroslavl en route to their first game of the season.
"In one moment, the family lost a loving father, and the whole country a hockey genius," said Igor Nemecek, president of the Slovak ice hockey federation.
"Palo (Demitra) was an idol and a role model for our young players," Nemecek said, adding that his national team jersey -- number 38 -- will be retired.
Three-time all-star player, Demitra had played for five NHL clubs during his career, including the St. Louis Blues and the Vancouver Canucks. He was planning to retire after one season with the Russian club.
Demitra, who was 36 years old, is survived by his wife Maria, a son and a daughter.