In a surface acoustic wave apparatus, a surface acoustic wave element for obtaining a convolution signal is housed in a recess of a substrate. Since the surface acoustic wave element is housed in the recess of the substrate in this surface acoustic wave apparatus, the apparatus can be compactified. This effect of compactification is remarkable, because the surface acoustic wave element has an output electrode for obtaining the convolution signal and thus originally has a big element size. When a laminate substrate is used as the substrate, a configuration for effectively using surfaces of respective layers may be arranged in such a manner that output wiring of the convolution signal is separately formed in the layers. This further enhances the effect of compactification. There are further disclosed a spread spectrum signal receiver using the above surface acoustic wave apparatus for receiving a spread spectrum signal, and a spread spectrum communication system using the spread spectrum signal receiver.