We have measured dependence of electron density ne on hydrogen dilution ratio R= [H2]/([SiH4]+[H2]) in the multi-hollow discharges with or without magnetic fields to obtain information about the deposition rate enhancement due to hydrogen dilution and applying the magnetic fields. The R dependence of the ne did not correlate with that of the deposition rate. The ne exponentially decreases with a distance from the discharges z. The ne decreases faster for higher R. These complicated behaviors of ne may be explained by electron attachment to the clusters generated in the SiH4+H2 discharges. For R=0, the ne was almost same value regardless with or without magnetic fields. For R=1, ne with magnetic fields was 1/10 of that without magnetic fields. We also found that, for R=0, ne drastically decreased with increasing the z, while for R=1, ne showed a gradual decrease with z. The effects of applying magnetic fields on the deposition are unclear but applying the magnetic fields may affect the electron energy distribution.