Takashi Ichinose and Masato Wakayama On the Spectral Zeta Function for the Non-commutative Harmonic Oscillator (35K, LaTeX 2e) ABSTRACT. The spectral zeta function for the so-called non-commutative harmonic oscillator is able to be meromorphically extended to the whole complex plane, having only one simple pole at the same point $s=1$ where Riemann's zeta function $\zeta(s)$ has, and possesses a trivial zero at each non-positive even integer. The essential part of its proof is sketched. A new result is also given on the lower and upper bounds of the eigenvalues of the non-commutative harmonic oscillator.