Abstract: An electromagnetic sensor formed by integral resin molding of a sensing device in which a pointed protrusion and an apertured protrusion for positioning capable of complementally engagement to each other are provided one at an axial end face of the sensing device and the other at an inner surface of a molding die. A plurality of circumferentially spaced apart axially extending portions in an intimate contact with an inner circumference of the molding die are provided to the outer circumference at a lower portion of a bobbin of the sensing device. The positioning protrusion on an axial end face of the sensing device is shaped such that the size in a direction perpendicular to a streamline of the resin is gradually decreased as it is away from a resin injection gate. The sensing portion is positioned stably in the molding die, resin molding can be applied as far as the top end of the pole piece to provide protection, and water proofness of the sensor is improved by intact contact with the resin.