We present broad band photometry and spectroscopic observations of the host galaxy of GRB 030329. Analysis of the spectral emission lines shows that the host is likely a low metallicity galaxy (Z 6 0.004). The spectral energy distribution (SED) constructed with the photometric points has been fitted using synthetic and observational templates. The best SED fit is obtained with a starburst template with an age of 6150 Myr and an extinction Av 6 0.6. We find that the GRB 030329 host galaxy is a subluminous galaxy (L 6 0.016 L*) with a stellar mass of 108 M. Three independent diagnostics, based on the restframe UV continuum, the O II, and the Balmer emission lines, provide a consistent unextinguished star formation rate of 60.6 M yr-1, implying a high unextinguished specific star formation rate (634 M yr-1 (L/L*)-1). We estimate that the unextinguished specific star formation rate of the GRB 030329 host is higher than 693.5% of the galaxies at a similar redshift.