Catheter for cryogenic ablation, particularly for treating atrial fibrillation, comprising: a grip (12), a hollow catheter body (14) a mapping catheter lumen (28) extending within the catheter body (14) and axially movable relative to the catheter body (14),a tube for injecting cooling fluid (42) that extends between the mapping catheter lumen (28) and the catheter body (14) a mapping catheter (48) movable within the mapping catheter lumen (28) having an end loop portion (50) perpendicular to the longitudinal axis (A) of the catheter body (14), a cryogenic balloon (34) having a first end (36) fixed to the distal end of the mapping catheter lumen (28) and a second end (38) fixed to the distal end (18) of the catheter body (14), characterized in that the distal end (32) of said mapping catheter lumen (28) has an open and tip-free front surface (56), and in that said first end (56) of said cryogenic balloon (34) is folded-back towards the inside of said cryogenic chamber (40), so that in the inflated position, said cryogenic balloon (34) has a front ablation area (58) that extends beyond the front surface (56) of said mapping catheter lumen (28).
