The present invention relates to a fryer (10) provided with a containing structure (11) inside which at least a frying basin (15) is present, which is filled with oil up to a preset maximum level, each frying basin (15) being provided with at least one drum (17) for containing the food to be fried, the fryer (10) further being provided with a perforated lid (20) comprising pass through holes (25, 27) for the passage of vapor and gas going upwards and of condensed vapor going downwards and means for cooling (21, 22, 23) and condensing vapor passing through said holes, and support means (16) of said vapor cooling means (21, 22, 23), characterized in that it further comprises means for adjusting the vapor flow (28).