A nucleoside derivative represented by the following formula (1) is provided.Embedded image (In the formula (1), Y represents an unfused aromatic or heterocyclic hydrocarbon group or a condensed polycyclic hydrocarbon group, W 1 represents a hydrogen atom, a hydroxyl group protecting group, or a phosphoric acid ester group , W 2 represents a hydrogen atom, a hydroxyl group protecting group or a phosphoric ester group, and each of R 1, R 2 and R 3 independently represents a hydrogen atom or a linear saturated hydrocarbon group having 1 to 4 carbon atoms.
