A developing device to perform development by supplying toner, in a developer in which the toner and a carrier are mixed, to an electrostatic latent image formed on an image bearing member, the developing device comprising: a development member to attach the developer to an outer circumferential surface of the development member and supply the toner to the image bearing member; a first regulation member that comprises a first regulating portion arranged with a first gap between the outer circumferential surface of the development member and the first regulating portion; and a second regulation member disposed on an upstream side of the first regulation member in a rotational direction of the development member and comprising a second regulating portion arranged with second gaps between the outer circumferential surface of the development member and the second regulating portion, wherein the second gaps at a central portion and both end portions of the second regulation member, in a longitudinal direction of the development member, are greater than the first gap, and the second gaps (G1, G3) at both end portions are less than the second gap at the central portion, wherein a difference between the second gap at the central portion and the second gaps (G1, G3) at the both end portions is equal to or less than 1 mm. wherein the second regulation member is arranged to uniformly distribute pressure and density of the developer along a length of the outer circumferential surface of the development member; wherein the second regulating portion is configured to form a different pressure and a density of the developer at both end portions to a pressure and a density of the developer at the central portion in the longitudinal direction of the development member; and wherein the second regulation member is configured to form the different pressure such that the pressure and the density of the developer at the both end portions is higher than the pressure and the density of the developer at the central portion. a development member to attach the developer to an outer circumferential surface of the development member and supply the toner to the image bearing member; a first regulation member that comprises a first regulating portion arranged with a first gap between the outer circumferential surface of the development member and the first regulating portion; and a second regulation member disposed on an upstream side of the first regulation member in a rotational direction of the development member and comprising a second regulating portion arranged with second gaps between the outer circumferential surface of the development member and the second regulating portion, wherein the second gaps at a central portion and both end portions of the second regulation member, in a longitudinal direction of the development member, are greater than the first gap, and the second gaps (G1, G3) at both end portions are less than the second gap at the central portion, wherein a difference between the second gap at the central portion and the second gaps (G1, G3) at the both end portions is equal to or less than 1 mm. wherein the second regulation member is arranged to uniformly distribute pressure and density of the developer along a length of the outer circumferential surface of the development member; wherein the second regulating portion is configured to form a different pressure and a density of the developer at both end portions to a pressure and a density of the developer at the central portion in the longitudinal direction of the development member; and wherein the second regulation member is configured to form the different pressure such that the pressure and the density of the developer at the both end portions is higher than the pressure and the density of the developer at the central portion.