A developing apparatus includes a developer carrying member, disposed
opposite to an image bearing member, for carrying developer which is
caused to jump from the developer carrying member to the image bearing
member to develop an electrostatic latent image formed on said image
bearing member by creating an oscillation electric field between the
image bearing member and the developer carrying member at an opposing
portion where the image bearing member and the developer carrying member
are opposed to each other; and a jumping developer regulation member for
regulating an area in which the developer is caused to jump in the
opposing portion. The jumping developer regulation member is disposed
apart from the developer carried by the developer carrying member and is
an insulating member or an electrically floating member.