The dielectric constant of methane has been measured at 298.15 K for pressures up to 710 MPa. The density values determined from the dielectric constant as well as direct weighing measurements are compared with the equation of state developed by Setzmann and Wagner (1991). The deviations from the equation of state are about 0.05% in the low and high pressure regions and up to about 0.1% in the intermediate pressure storage.