A groove is provided in a magnet such that a first magnetic force region where an absolute value of a magnetic force of a component in a direction normal to a developer carrying member is 1 [nN] or less is formed on a surface of the developer carrying member on a downstream side of a third maximum peak position and on an upstream side of a second maximum peak position in a rotation direction of the developer carrying member, and a second magnetic force region where the absolute value of the magnetic force of the component in the direction normal to the developer carrying member is 1 [nN] or less is formed on the surface of the developer carrying member on a downstream side of a first maximum peak position and on an upstream side of the third maximum peak position in the rotation direction of the developer carrying member.
