The public suicide by the 77-year-old retired pharmacist quickly triggered an outpour of sympathy in a country where one in five is jobless and a sense of national humiliation has accompanied successive rounds of salary and pension cuts.
Just hours after the death, an impromptu shrine with candles, flowers and hand-written notes protesting the crisis sprung up in the central Syntagma square where the suicide occurred. Dozens of bystanders gathered to pay their respects.
One note nailed to a tree said "Enough is enough", while another asked "Who will be the next victim?".
The 'Indignant' protesters, who have turned out in the thousands against austerity measures imposed by foreign lenders in exchange for bailout loans, said they planned a march later on Wednesday.
"This is a human tragedy," government spokesman Pantelis Kapsis said as politicians in parliament decried the death.
Witnesses said the man put a gun to his head and pulled the trigger after yelling out: "I have debts, I can't stand this anymore."
Another passerby told Greek television the man said "I don't want to leave my debts to my children."
A suicide note found in his coat pocket blamed politicians and financial troubles for driving him to take his life, police said.
The government had "annihilated any hope for my survival and I could not get any justice. I cannot find any other form of struggle except a dignified end before I have to start scrounging for food from the trash"," the note said.