To provide a resin-coated long body which reduces a risk of separation of a coating resin layer from a core material even in the case of the core material having an inward recessed shape on an outer surface, and which can be simply manufactured.

A resin-coated long body P includes a metal core material 1 which has an inward recessed surface 2 formed on an outer surface along a longitudinal direction, and a coating resin layer 3 which coats the outer surface including the recessed surface 2 of the core material 1. On the recessed surface 2 of the core material 1 a dovetail groove-like anti-coming-off groove 23 is formed in the inward direction of the core material 1, so that the coating resin layer 3 can partially make an entry into the anti-coming-off groove 23.