Chesterfield paid the price for failing to take their chances as Peterborough kept another clean sheet away from home to boost their hopes of staying up.
Barry Fry's team have not let in a goal away from home since Boxing Day but they rode their luck as Chesterfield dominated the game but could not find a telling finish.
Glynn Hurst had three good chances in the first half and both David Reeves and Robert Edwards missed badly in the second.
Peterborough defended well and Fry made a triple substitution to try and change the match but admitted he was happy with a draw.
"I suppose I've got to be happy with a point away from home but the opportunities were there for us," Fry said.
Chesterfield manager Dave Rushbury knew his team should have found the net and he said: "What more do we have to do to score a goal?" His team were the sharper and more inventive throughout but the tone was set when Hurst headed over after Lee Harrison missed a corner.
The striker also put a header wide from eight yards and brought a reflex save from Harrison before the Peterborough keeper again did well to keep out an Edwards free kick.
But Harrison should have been beaten in the 64th minute when David Reeves beat the offside trap but after going round the keeper, he hesitated and the opportunity was wasted.
Peterborough almost snatched it near the end when the ball broke loose in front off of goal but Allan O'Hare made a great block just as substitute David Farrell was set to bury the chance.