A free-kick from Matt Grimes put the Grecians ahead and although the hosts had midfielder Sam Morsy sent-off, a Eoin Doyle penalty earned them a point 12 minutes from time.
Exeter got the start they wanted in the 18th minute when a free-kick just outside the area from Grimes deflected off the wall and into the back of the net, leaving goalkeeper Tommy Lee helpless.
Chesterfield created little until a Marc Richards free-kick forced Cristy Pym into a diving save five minutes before half-time.
Richards glanced a header just wide early in the second half but Exeter missed a great chance to double their lead when a mistake by Liam Cooper in the 52nd minute set up John O'Flynn but his shot went behind off Lee's legs.
Chesterfield were reduced to 10 men in the 75th minute when Morsy was shown a straight red card for a two-footed lunge on Grimes but the Spireites were level three minutes later when Doyle scored from the penalty spot after he was tripped by Danny Butterfield.
Lee made a stunning save to deny Scott Bennett in the 85th minute and Gary Roberts could have won it for Chesterfield but fired into the side netting.