To enhance characteristics of a case where a cycloolefinic compound including no polar groups is used such as low adhesion friendliness with other materials, low compatibilities with other compounds such as curatives, epoxy groups, etc. and of a case where a cycloolefinic compound including polar groups is used such as high water absorbency, lengthy propagation delay time, low glass transition point, low heat resistance, etc.

The provided polymer includes structural units derived from a cycloolefinic compound and structural units derived from allyl isocyanurate. A resin composition including the polymer is also provided.