An epitaxial silicon wafer includes: a silicon wafer doped with phosphorus as a dopant and having an electrical resistivity of less than 1.0 m Ω·cm; and an epitaxial film formed on the silicon wafer. The silicon wafer includes: a main surface to which a (100) plane is inclined; and a [100] axis that is perpendicular to the (100) plane and inclined at an angle ranging from 0°30′ to 0°55′ in any direction with respect to an axis perpendicular to the main surface. The epitaxial silicon wafer has at most 1/cm2 of a density of a hillock defect generated thereon.