A manufacturing method for a reactor in which resin for covering at least a part of a coil is formed integrally with the coil comprise a step of manufacturing a molded product and a step of attaching a temperature sensor such that the temperature sensor is opposed to a first face. The step of manufacturing the molded product includes following i) to iii): i) arranging the reactor in a cavity space for injection-molding of resin; ii) fixing the coil with the surface of a mold brought into contact with the first face and a second face located at positions which sandwich the coil on the periphery of the coil; and iii) injecting resin into the cavity space to cover at least a coil surface around the first face and a coil surface around the second face with the resin, with the first face and the second face exposed.