Charlie Hebdo columnist Dr Patrick Pelloux emotionally told French TV channel iTele that the magazine would continue, as not doing so would mean the killers had won.
Quietly crying, the emergency doctor added that, although it would be very difficult to produce the issue, "stupidity will not win".
Paying tribute to his colleagues, Dr Pelloux said they were "extraordinary" men and women who were shot at in the middle of an editorial conference.
He said he was at a meeting of firefighters a short distance from the Charlie Hebdo offices in Paris when he received a call from one of the paper's graphic designers to say he was needed.
Describing what it felt like to be one of the first emergency workers on the scene, Dr Pelloux said: "It was horrible. Horrible. Many of them were already gone, because they were gunned down execution-style. We managed to save others.
"I came here to tell you that the paper's going to continue, because they haven't won. And that Charb, Cabu, Wolinski, Bernard Maris, Honore, Elsa, Tignous, Moustafa, the bodyguard who was killed who was in charge of our security – they didn't die in vain."
He said there was no hate towards Muslims, but everyone had to work to keep the values of the Republic alive.
After the massacre, the newspaper's website displayed no content apart from a black page with white text reading Je Suis Charlie, translated into many other languages including Arabic.
It has been reported locally that for the next issue 250,000 euros will be taken from a press diversity fund managed by French editors.
Google is expected to give $300,000 and the Guardian Media Group has pledged £100,000 to the magazine, Guardian editor Alan Rusbridger announced last night.
It is expected that Charle Hebdo will be published as scheduled next week with a planned print run of 1m rather than the usual 60,000.