A developing device, comprising: a developing roller arranged to face an image carrier on which an electrostatic latent image is to be formed, for supplying toner to the image carrier in a facing region with respect to the image carrier during image formation; a toner supplying roller arranged to face the developing roller, for supplying the toner to the developing roller in a facing region with respect to the developing roller; a regulation blade arranged to face the toner supplying roller at predetermined distance; and a casing for housing the developing roller, the toner supplying roller, and the regulation blade, the casing includes a toner catching support member which faces a lower portion of the developing roller and of the toner supplying roller between the regulation blade and the image carrier, and which forms a wall portion inclined downward in a direction of from the developing roller to the toner supplying roller; and the developing device further comprises: a toner catching member arranged on an upper surface of the toner catching support member along a longitudinal direction thereof, for catching toner which drops from the developing roller; and vibration generating means for vibrating the toner catching member, wherein the toner catching member is configured to be vibrated by the vibration generating means except during the image formation and the toner supplying roller is configured to be rotated in a direction reverse to a rotating direction during the image formation. a developing roller arranged to face an image carrier on which an electrostatic latent image is to be formed, for supplying toner to the image carrier in a facing region with respect to the image carrier during image formation; a toner supplying roller arranged to face the developing roller, for supplying the toner to the developing roller in a facing region with respect to the developing roller; a regulation blade arranged to face the toner supplying roller at predetermined distance; and a casing for housing the developing roller, the toner supplying roller, and the regulation blade, the casing includes a toner catching support member which faces a lower portion of the developing roller and of the toner supplying roller between the regulation blade and the image carrier, and which forms a wall portion inclined downward in a direction of from the developing roller to the toner supplying roller; and the developing device further comprises: a toner catching member arranged on an upper surface of the toner catching support member along a longitudinal direction thereof, for catching toner which drops from the developing roller; and vibration generating means for vibrating the toner catching member, wherein the toner catching member is configured to be vibrated by the vibration generating means except during the image formation and the toner supplying roller is configured to be rotated in a direction reverse to a rotating direction during the image formation. a toner catching member arranged on an upper surface of the toner catching support member along a longitudinal direction thereof, for catching toner which drops from the developing roller; and vibration generating means for vibrating the toner catching member, wherein the toner catching member is configured to be vibrated by the vibration generating means except during the image formation and the toner supplying roller is configured to be rotated in a direction reverse to a rotating direction during the image formation.