The Łojasiewicz exponent of a set of weighted homogeneous ideals

We give an expression for the Łojasiewicz exponent of a set of ideals which are pieces of a weighted homogeneous filtration. We also study the application of this formula to the computation of the Łojasiewicz exponent of the gradient of a semi-weighted homogeneous function (Cn,0)→(C,0) with an isolated singularity at the origin.