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 (T); a developing chamber in which the developer bearing member is provided; an accommodating chamber configured to accommodate the developer (T), 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 (T) 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 (T) 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 (F) 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 (F) of the conveying member . a developer bearing member configured to bear developer (T); a developing chamber in which the developer bearing member is provided; an accommodating chamber configured to accommodate the developer (T), 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 (T) 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 (T) 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 (F) 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 (F) of the conveying member . <EOS>