It is well-known that the Fourier coefficients of Siegel–Eisenstein series can be expressed in terms of the Siegel series. The functional equation of the Siegel series of a quadratic form over class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302104&_mathId=si1.gif&_user=111111111&_pii=S0022314X16302104&_rdoc=1&_issn=0022314X&md5=64550c722df22f4742f32dc728bc593c" title="Click to view the MathML source">Qpclass="mathContainer hidden">class="mathCode"> was first proved by Katsurada. In this paper, we prove the functional equation of the Siegel series over a non-archimedean local field of characteristic 0 by using the representation theoretic argument by Kudla and Sweet.