A developing apparatus comprising: a developing container configured to accommodate a developer containing toner and carrier; a developer carrying member rotatably supported by said developing container to carry the developer to a position for developing an electrostatic latent image formed on an image bearing member; a regulating portion provided opposed to said developer carrying member with a space therebetween to regulate an amount of the developer carried on said developer carrying member; and a magnet fixed inside of said developer carrying member and having a plurality of magnetic poles to generate a magnetic field for said developer carrying member to carrying the developer, wherein said plurality of magnetic poles include a developer regulation pole provided at a position opposed to said regulating portion, wherein in a rotational direction of said developer carrying member, a half-peak center portion position is at a center of a half-peak width of a magnetic flux density distribution of said developer regulation pole in a normal direction component relative to said developer carrying member, characterized in that said developer regulation pole is formed such that, in the rotational direction of said developer carrying member, said half-peak center portion position is not less than 3° and not more than 20° upstream of a maximum peak position at which the maximum magnetic flux of said developer regulation pole is provided, and in the rotational direction of said developer carrying member, a position where said developer carrying member is closest to said regulating portion is upstream of the maximum peak position. a developing container configured to accommodate a developer containing toner and carrier; a developer carrying member rotatably supported by said developing container to carry the developer to a position for developing an electrostatic latent image formed on an image bearing member; a regulating portion provided opposed to said developer carrying member with a space therebetween to regulate an amount of the developer carried on said developer carrying member; and a magnet fixed inside of said developer carrying member and having a plurality of magnetic poles to generate a magnetic field for said developer carrying member to carrying the developer, wherein said plurality of magnetic poles include a developer regulation pole provided at a position opposed to said regulating portion, wherein in a rotational direction of said developer carrying member, a half-peak center portion position is at a center of a half-peak width of a magnetic flux density distribution of said developer regulation pole in a normal direction component relative to said developer carrying member, characterized in that said developer regulation pole is formed such that, in the rotational direction of said developer carrying member, said half-peak center portion position is not less than 3° and not more than 20° upstream of a maximum peak position at which the maximum magnetic flux of said developer regulation pole is provided, and in the rotational direction of said developer carrying member, a position where said developer carrying member is closest to said regulating portion is upstream of the maximum peak position.