A mechanical seal (1; 40; 59) configured to be interposed between a rotating shaft (2) and a fixed body (3) provided with an aperture (4) through which the shaft (2) extends, particularly for a recirculation pump of the cooling liquid of a motor, comprising a fixed part (5) and a rotating part (7) provided with respective sealing rings (6, 8) cooperating frontally with each other under an axial load exerted by a spring (33), and an absorbing material element (35) for absorbing at least temporarily possible leaks of fluid leaking through the sealing rings (6, 8) fixed to the fixed part (5).