We report the first detailed spectroscopic observations of the recently identified intermediate polar RXJ0028.8+5917/V709 Cas .
We discovered that the system shows significant EW \sim ( 2-4 ) Å broad absorptions affecting the Balmer lines from H \delta to H \beta .
These broad absorptions are interpreted as the contribution of an underlying DA log g=8 white dwarf at a temperature of \sim 23 000 K , contributing \sim 17 % ( at 4500 Å ) to the overall flux .
This is the first direct detection of a white dwarf in an intermediate polar system .
The absence of significant Zeeman splitting indicates a magnetic field lower than 10 MG , confirming that , at least in some cases , intermediate polars have weaker fields than polars .