A method for inspecting a metal surface (12) includes providing a first laser source (14) that is arranged to generate a first laser beam having a first wavelength comprised between 1000 nm and 1100 nm and a power higher than 1 W; providing a second laser source (16) that is arranged to generate a second laser beam having a second wavelength comprised between 1500 nm and 1800 nm and a power higher than 1 W; activating one of the first and second laser sources and transmitting the first or second laser beam to the entrance (22) of an optic (18); scanning the metal surface (12) with the laser beam projected by the optic; and acquiring at least one image of the infrared radiation emitted by the metal surface (12).