A distance sensor equipped with a mount for mounting the sensor in a mount hole of a bumper of a vehicle. The mount includes a casing with a sensor holder, a bezel, and a resin-made retainer. The bezel is made up of a cylindrical member joined to the sensor holder and a flange having an outer diameter greater than an inner diameter of the mount hole. The retainer includes an annular base joined to the bezel, a plurality of arms, and a plurality of protrusions. The protrusions extend from ends of the arms radially outward of the base and serve to establish a snap-fit on a peripheral edge of the mount hole, thereby nipping a wall of the bumper between the protrusions and the flange tightly to secure the distance sensor to the bumper.