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 (N1) 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 (N1) in a normal direction component relative to said developer carrying member , characterized in that said developer regulation pole (N1) 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 (N1) 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 (N1) 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 (N1) in a normal direction component relative to said developer carrying member , characterized in that said developer regulation pole (N1) 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 (N1) 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. <EOS>