The device for generating an air flow for cooling a heat dissipating electronic element such as an LED comprises a channel (12,56) extending between an inlet portion (18) upstream of the air flow to be generated and an outlet portion (20) downstream of the air flow to be generated, wherein the channel (12,56) comprises at least two substantially opposite side surfaces (14). Moreover, the device is provided with a first bendable air ventilating blade (10,58) arranged within the channel (12,56) and having an overall longitudinal extension substantially coinciding with the extension of the channel (12,56), with a first longitudinal end (24,62) arranged upstream of the air ventilating blade (10,58) flow to be generated and a second end (28,70) arranged downstream of the air flow to be generated. The first air ventilating blade (10,58) with its first end (24,62) is fixedly arranged and has its second end (28,70) is reciprocatingly arranged. Furthermore, the device comprises a driving means (32,34,36,66,68) for reciprocating the second end (28,70) of the air ventilating blade (10,58) in a direction between the two substantially opposite side surfaces of the channel (12,56).