This paper describes a new technique, called Empirical Mode Decomposition (EMD), which allows the decomposition of one-dimensional signals into intrinsic oscillatory modes. Each component, called Intrinsic Mode Function (IMF), has nice properties which allow the calculation of a meaningful instantaneous frequency. Applied to a seismic trace, this technique allows to study the different intrinsic oscillatory modes of the seismic trace, and to study the instantaneous frequency of these different modes. Applied to a seismic section, it provides new frequency attributes.