PURPOSE: To obtain the subject composition containing a specific photopolymerization initiator, specified in both the pencil hardness of the cured film therein and peak absorbance, excellent in flexibility, thick film curability and chemical resistance, and useful for molding the arrangement zone of optical microelements such as microlens arrays.

CONSTITUTION: This resin composition is obtained by incorporating a resin component made chiefly from a monomer having at least one functional group with a photopolymerization initiator reacting on irradiating curing energy rays and generating ions or radicals. This composition has the following characteristics: the pencil hardness of the cured film therein is HB or lower; and this composition and/or the cured film have a peak absorbance of ≥0.02/μm to the rays of light 320-400nm in wavelength. It is preferable that the monomer be of the formula (≥200 in the molecular weight of R), the curing energy rays of light be ultraviolet light, and this composition contain a ultraviolet absorbing material.