A developing device includes: an agitation member including an agitation film; and a housing including a first frame and a second frame jointed to the first frame. The second frame includes: a first contact part configured to contact the agitation film, and a second contact part configured to contact the agitation film, arranged at a downstream side of the first contact part, the second contact part protruding towards the first frame. A first distance from the rotational axis line to the first contact part, as seen from a direction of the rotational axis line, is gradually increased towards a downstream side with respect to the rotating direction. A second distance from the rotational axis line to the second contact part is equal to or greater than a maximum distance from the rotational axis line to the first contact part.