A portable lamp, such as a headlamp, having control of the light power without the need for any manual switch is presented. The lamp comprises a power module for powering one or more light sources, first proximity detectors for detecting an object such as a finger moving close to the lamp, in one direction or another along a first axis X-X; and a control module receiving information generated by said first proximity detectors, said control module being configured for generating, from the direction of the movement of said object, a control information for switching-on, switching-off or adjusting the level of the intensity of the light power.