The first half was scrappy and disjointed although Barnet had looked the more accomplished side and took a 32nd minute lead through Ismail Yakubu.
But Chesterfield came to life in the second half and Hall levelled in the 74th minute following a corner.
The Spireites had been well below par before the interval when passes went astray and the service to the strikers was virtually non-existent.
Barnet created few clear openings until the 32nd minute when a corner was played back across goal by Gary Breen and Yakubu sidefooted in from four yards for his fourth of the season.
Chesterfield had to get better and they did although they were still frustrated by some strong Bees defending and the reflexes of goalkeeper Lee Harrison.
Harrison did well to tip over a looping header from Martin Gritton in the 69th minute and then turned away a 25-yard shot from substitute Lewis Montrose.
But from the resulting corner, Aaron Downes headed back into the six-yard box and Hall reacted smartly to beat Harrison.
It was now Chesterfield who sensed victory and they might have taken the lead, but for another good save by Harrison who raced off his line to throw himself at the feet of midfielder Lloyd Kerry.
Both teams went close to grabbing a winner in the final minutes with Matt Lockwood seeing a goalbound shot blocked by a Chesterfield shirt, although a draw was probably a fair result.