It is shown that the use of direct volume magnetostatic waves (FVMSW) in epitaxial ferrite film can be the basis for convolver construction. A theoretical analysis confirmed that the output signal corresponds to the double compressed in time (because of counter motion waves that carry signals) convolution function at the input signals. Defined expression for calculating signal of convolution, which takes into account the frequency characteristics of a magnetized film as waveguide structure, the sizes of the film and the antenna in form a rectangular loop, the induced voltage which corresponds to the signal convolution. For FVMSW limit signals, beyond which there is an unstable nonlinear phenomena associated with parametric excitation of exchange spin waves, tall, can give signals of a higher level and get a good signal/ noise ratio for the signal convolution.