Horrific CCTV footage played in court showed Chris Parker wandering between stricken and dying victims left bleeding on the floor.
He repeatedly returned to Pauline Healey, whose granddaughter lay dying nearby, before leaning over her body and taking her handbag to steal her purse.
Parker, 33, pleaded guilty at Manchester Crown Court to two counts of theft and one of fraud.
Within hours of taking the purse of Mrs Healey, who was injured in the blast, he was using her bank card at a local McDonald’s.
He failed to turn up in court on Tuesday and was found hiding in the loft of a house in Halifax, West Yorkshire, where he was arrested.
A total of 23 people were killed when a homemade bomb was set off as fans were leaving an Ariana Grande concert.
More than 500 people were injured.