But the Hatters dominated most of the game and should really have taken all three points.
Chesterfield, who struggled to find any sort of form, looked vulnerable right from the start and after only ten minutes Tom Craddock put Paul McVeigh in the clear, but the midfielder's shot was pushed away by Tommy Lee.
Craddock, who had an outstanding game, was in the thick of the action again on 20 minutes when he collected a pass from Kevin Gallen, but fired wide from a good position.
Little was seen of the Chesterfield attack and Luton had a great chance just two minutes before the half-time break. A cross from Rossi Jarvis picked out Michael Spillane, whose close-range header was blocked on the line by Lee.
Chesterfield went in front with their first real attack of the game. Jamie Lowry headed on a long clearance for Jamie Ward, who easily beat two defenders before firing in a left-foot shot.
The second half was still dominated by Luton. They finally levelled in the 56th minute, when an excellent pass from McVeigh found Craddock, who beat Lee with a first-time shot.
Craddock was unlucky in the 71st minute when he appeared to be brought down inside the box by Aaron Downes, only to be booked for diving.
Chesterfield then went back in front when Ward set up teenager Scott Bowden in the 82nd minute. The 19-year-old calmly beat Conrad Logan from 15 yards to net his first Football League goal.
But Luton did not give up and piled on the pressure in the closing minutes. Craddock had a far-post header saved by Lee, then deep into stoppage time Lee flung himself to his left to keep a goalbound header from Asa Hall.
The resulting corner brought Luton's equaliser with Ian Roper glancing home a header to convert Jake Howells' cross.