Striker Henry, left unmarked in the area, volleyed home a free-kick from Zinedine Zidane [ Images ] for the winner after 57 minutes.
Les Bleus, who had stunned Brazil 3-0 in the 1998 final, produced a superb performance to set up a match with Portugal on Wednesday in Munich for a place in the July 9 final.
Five-times champions Brazil, who were hoping to reach the World Cup final for the fourth time in succession, looked nervous throughout a game of high quality.
France's win means the great Zidane, who was back to his brilliant best in Frankfurt, has not played his last match yet.
The 34-year-old maestro, who will retire after the finals, lived up to the occasion, as did the entire French team.
The finest bunch of players to wear French colours when they were world champions began the finals sluggishly but proved at Brazil's expense that they are still a formidable outfit.
Brazil showed more initiative in a tight, tactical start dominated by an intense battle for possession and threatened after 11 minutes as Ronaldo [ Images ] headed a Ronaldinho [ Images ] free-kick over.
France, gradually winning more balls in midfield and gaining confidence, dominated their prestigious opponents for most of a frustrating first period with few highlights.
Les Bleus hardly created a chance in those first 45 minutes but neither did their hosts, whose feared forwards failed to breach a watertight French defence.
The closest France came was in added time before the break when Patrick Vieira, beautifully set up by some Zidane wizardry, charged towards goal.
It took a late, dangerous tackle from Brazil defender Juan, who collected a yellow card for the offence, to stop the France midfielder.
France started the second half in determined fashion, Vieira heading a Zidane free kick wide before Henry headed into the net, also from set piece, only to be flagged offside.
Shortly after France opened the scoring, Juan almost doubled their advantage with an own goal as he sliced a clearance aiming at a cross by the ever-dangerous Franck Ribery [ Images ].
Clearly in control from then on, France thrilled the crowd with fluent moves and despite Ronaldinho's efforts, including a free kick over the bar, they savoured a deserved victory.