Envelope solitons of hybrid spin electromagnetic waves have been experimentally observed. These solitons are formed at the self-generation of spin electromagnetic waves in an active ring cavity, where a ferrite-ferroelectric layered multiferroic structure serves as a nonlinear waveguide dispersive medium. The effect of the permittivity of the structure on the nonlinear properties of spin electromagnetic waves has been demonstrated. The hybrid wave nature of solitons has been experimentally and theoretically justified.