A developing apparatus configured to be attached to an apparatus main body of an image forming apparatus, the developing apparatus comprising: a developer bearing member configured to bear developer; a developing chamber in which the developer bearing member is provided; an accommodating chamber configured to accommodate the developer, the accommodating chamber having a concave portion in an inner wall thereof and an opening; a conveying member including a rotating shaft parallel to an axial direction of the developer bearing member and a sheet member attached to the rotating shaft, a first end of the sheet member being attached to the rotating shaft in a direction perpendicular to the axial direction of the developer bearing member, the conveying member being configured to stir and convey the developer toward the developing chamber through the opening by rotating of the sheet member together with the rotating shaft; and a first detecting portion and a second detecting portion for detecting an amount of the developer in use of capacitance, wherein the concave portion is within a virtual circle formed by a free end of the sheet member in an extended state rotating about a rotational axis of the rotating shaft when viewed in a longitudinal direction of the rotating shaft, the free end of the sheet member being a second end of the sheet member opposite to the first end in the direction perpendicular to the axial direction of the developer bearing member, wherein the accommodating chamber is positioned under the developing chamber in a state that the developing apparatus is attached to the apparatus main body of the image forming apparatus, the first detecting portion is provided on a downstream wall surface (18d1) of the concave portion with respect to a rotating direction of the conveying member, and the second detecting portion is provided on an upstream wall surface (18d2) of the concave portion with respect to the rotating direction of the conveying member. a developer bearing member configured to bear developer; a developing chamber in which the developer bearing member is provided; an accommodating chamber configured to accommodate the developer, the accommodating chamber having a concave portion in an inner wall thereof and an opening; a conveying member including a rotating shaft parallel to an axial direction of the developer bearing member and a sheet member attached to the rotating shaft, a first end of the sheet member being attached to the rotating shaft in a direction perpendicular to the axial direction of the developer bearing member, the conveying member being configured to stir and convey the developer toward the developing chamber through the opening by rotating of the sheet member together with the rotating shaft; and a first detecting portion and a second detecting portion for detecting an amount of the developer in use of capacitance, wherein the concave portion is within a virtual circle formed by a free end of the sheet member in an extended state rotating about a rotational axis of the rotating shaft when viewed in a longitudinal direction of the rotating shaft, the free end of the sheet member being a second end of the sheet member opposite to the first end in the direction perpendicular to the axial direction of the developer bearing member, wherein the accommodating chamber is positioned under the developing chamber in a state that the developing apparatus is attached to the apparatus main body of the image forming apparatus, the first detecting portion is provided on a downstream wall surface (18d1) of the concave portion with respect to a rotating direction of the conveying member, and the second detecting portion is provided on an upstream wall surface (18d2) of the concave portion with respect to the rotating direction of the conveying member.