  Using the recently installed Gemini Planet Imager (GPI), we have taken the
first H-band spectrum of the planetary companion to the nearby young star beta
Pictoris. GPI is designed to image and provide low-resolution spectra of
Jupiter sized, self-luminous planetary companions around young nearby stars.
These observations were taken covering the H-band (1.65 microns). The spectrum
has a resolving power of $\sim$ 45 and demonstrates the distinctive triangular
shape of a cool substellar object with low surface gravity. Using atmospheric
models, we find an effective temperature of $1650 \pm 50$ K and a surface
gravity of $\log(g) = 4.0 \pm 0.25$ (cgs units). These values agree well with
predictions from planetary evolution models for a gas giant with mass between
10 and 12 $M_{\rm Jup}$ and age between 10 and 20 Myrs.
