Provided is an energy ray-curable elastomer composition which can increase the inter-crosslinking point molecular weight without changing the kind of an energy ray-curable compound before cured and which provides an oligomer-cured substance having a braking elongation compatible with a processability, to be specific, an energy ray-curable elastomer composition containing (A) an energy ray-curable compound having a (meth)acryloyl group and (B) a polythiol compound having 2 to 6 mercapto groups in a molecule, wherein a functional group number ratio of the (meth)acryloyl group in the above composition to the mercapto group in the component (B) is 100:0.1 to 100:5n (n is the number of the mercapto group in a molecule of the polythiol compound).