Phosphorus abundances of ~80 apparently bright sharp-lined early-to-late B-type stars on the upper main sequence are determined by applying the non-LTE analysis to the PII line at 6043.084{AA}, with the aim of getting information on the P abundance of the galactic gas (from which these young stars were formed) in comparison to the reference solar abundance (A_{sun}_~5.45). These sample stars turned out to be divided into two distinct groups with respect to their P abundances. Chemically peculiar late B-type stars of HgMn group show considerable overabundances of P (supersolar by ~0.5-1.5dex), the extent of which progressively increases with Teff. In contrast, the P abundances of normal B-type stars are comparatively homogeneous, though a notable difference is observed between the LTE and non-LTE cases. Although their LTE abundances are near-solar, a slight gradual trend with Teff is observed. However, after applying the negative non-LTE corrections (amounting ~0.1-0.5dex), this Teff -dependence is successfully removed, but the resulting non-LTE abundances (their mean is ~5.20 ) are appreciably underabundant relative to the Sun by ~0.2-0.3dex. The cause of this systematic discrepancy, contradicting the galactic chemical evolution, is yet to be investigated.