Cazeneuve, a Socialist, accused Le Pen of “shamelessly exploiting fear and emotion for purely political ends,” just two days before the first round ofFrance's presidential election.
The head of the anti-immigration National Front (FN) “is seeking, as she does after every tragedy, to take advantage of it”.
Le Pen is tipped to be one of the top two vote-getters who will qualify on Sunday for a decisive May 7 runoff.
FN vice president Florian Philippot responded to Cazeneuve on Twitter, saying the prime minister should “have resigned a long time ago for his incoherence and lack of rigour”.
In the wake of the attack, Le Pen said “this war against us is ceaseless and merciless,” and charged that the outgoing Socialist government and its rightwing predecessor had “done everything to ensure that we lose” the fight.
Le Pen, widely seen as taking the hardest line on security among the candidates, called for France to “immediately” take back control of its own borders from the European Union and deport all foreigners on a terror watchlist.
Cazenueve said Le Pen had “pretended not to know that it is this government that reinstated control of the borders” after the attacks of November 2015 in Paris that claimed 130 lives.
He noted that since then 80,000 people have been turned away at border checks, while 117 people have been deported from France for “terrorist activities”.
Cazeneuve also criticised conservative candidate Francois Fillon, who reiterated a pledge to create 10,000 new police jobs.
“How can you can believe a candidate on this subject when he cut 13,000 from the security forces when he was prime minister” in 2007-12, said Cazeneuve, who was interior minister before becoming head of government in December.
Cazeneuve also pointed out Fillon's campaign pledge to cut half a million jobs from the civil service if elected.
Fillon is among four candidates bunched at the head of the pack going into Sunday's first-round vote.