Demy, Greece’s representative in the 2017 Eurovision song contest, was two of 10 to qualify for the final in the first round of heats in Kiev, Ukraine.
The 25-year-old singer performed “This Is Love,” a song composed by Dimitris Kontopoulos with lyrics from Romy Papadea and John Ballard.
Tuesday's other qualifiers for the final were Portugal, Cyprus, Sweden, Armenia, Moldova, Azerbaijan, Poland, Australia and Belgium. Eight countries missed out on a final place.
A second semi-final will be held on Thursday.
“I’m really lucky and I’m really happy for today and for all the support. I trust myself and I trust my team, I’m sure we’re going to give our best performance in the final now that we have the chance to do that. This is love,” Demy told a press conference after the semi-final.
The final will take place on Saturday.