An ethylene (co)polymer of the present invention is a (co)polymer with excellent moldability and mechanical properties and either an ethylene homopolymer or a copolymer of ethylene and an alpha -olefin of 4 to 20 carbon atoms. The (co)polymer has methyl branches measured by <13>C-NMR less than 0.1 in number per 1,000 carbon atoms and Mw/Mn measured by GPC not lower than 1.8 and lower than 4.5. The (co)polymer is either an ethylene homopolymer or a copolymer of ethylene and an alpha -olefin of 3 to 20 carbon atoms. The melt tension (MT) and the swell ratio (SR) satisfy the relation; log(MT) > 12.9 - 7.15 x SR; and the intrinsic viscosity (Ä eta Ü) and the melt flow rate (MFR) satisfy the relation; Ä eta Ü > 1.85 x MFR<-0.192> in the case of MFR < 1 and the relation; Ä eta Ü > 1.85 x MFR<-0.213> in the case of MFR ≥ 1. Such an ethylene (co)polymer can be usable for various molding applications and especially suitable for pipes.