Provided is an active energy ray curable resin composition for the formation of a hard coating layer on a thermoplastic resin product, where the hard coating layer is one having good resistance to scratches and abrasion and strong resistance to impact and weather or one having very good resistance to scratches and abrasion. The composition contains a urethane (meth)acrylate (A) having an average number of functional groups of 3 to 6 and having, in molecular skeleton, an organic group corresponding to a tricyclodecanedimethanol represented by following Formula (1), except for removing two hydrogen atoms of two hydroxyl groups therefrom; and a microparticulate silica (S) having a volume median diameter of 1 to 100 nm as determined by dynamic light scattering. The composition contains 10 to 40 percent by weight of the urethane (meth)acrylate (A) and 10 to 60 percent by weight of the microparticulate silica (S) based on the total weight of non-volatile matter in the composition.