A grommet for fixing an object such as a cable along a groove portion of a channel-type steel material can be fixed or freely stopped by using lips of the channel-type steel material. A grommet includes a base leg portion and a flange portion. The base leg portion includes elastic leg pieces elastically protruding toward an outside, bent toward an inside by being pressed by lips when inserted into an inside of a space of the lips, and restored to original state inside a groove portion after passing through the inside of the space of the lips so as to sandwich the lips between the elastic leg pieces and the flange portion from an inside and an outside. At least either one of the base leg portion or the flange portion includes a locking device for locking the object or a locking device of the object.