Provided are a magnetic transducer and a thin film magnetic head having good thermal stability and capable of obtaining a high exchange coupling magnetic field, a method of manufacturing a magnetic transducer and a method of a manufacturing a thin film magnetic head. An MR element has a stack having a stacked structure comprising an underlayer, a crystal-growth inhibitor layer, a first soft magnetic layer, a second soft magnetic layer, a nonmagnetic layer, a ferromagnetic layer, an antiferromagnetic layer and a cap layer, which are stacked in sequence. The ferromagnetic layer has an inner ferromagnetic layer, a coupling layer and an outer ferromagnetic layer, which are stacked in this order on the nonmagnetic layer. The crystal-growth inhibitor layer inhibits crystal growth of the layers formed on the crystal-growth inhibitor layer, thereby limiting an average in-surface particle diameter of the inner ferromagnetic layer to within the range of from 3 nm to 8 nm inclusive, so that an interface between the coupling layer and the inner ferromagnetic layer becomes flattened.